Q is for... Quarks

Diminutive but powerful robot servants of the Dominators, a war-like race of people who claimed to be the Masters of the Ten Galaxies.

Quarks were squat box-like bipedal machines, with spiked, spherical heads. Their arms folded into their bodies and were designed to hold a variety of tools and weapons. They could communicate verbally, having a shrill, child-like voice.

One drawback to the robots was that they had limited energy levels and had to recharge frequently. Quarks could distribute power between themselves to equalise their energy levels.

The Doctor and his companions encountered a party of Quarks when a lone Dominator spaceship landed on the tranquil world of Dulkis, determined to assess its population as suitable for slave labour. Probationer Toba used them to kill a party of young thrill-seekers who had wandered too close to the island where their ship - and the TARDIS - had landed. This angered his commander, Rago, as it used up valuable power and deprived them of natives to interrogate. Toba repeatedly went against Rago's orders to further kill prisoners and destroy infrastructure on the island - to the point that the Quarks' energy levels were threatened. When it became clear that the pacifist Dulcians were unfit to be enslaved, it was decided to destroy the planet by transforming it into a radioactive mass - fuel for the Dominator war fleet. Quarks were instructed to prepare drill sites around a central borehole. They were also used to oversee Dulcian prisoners who were forced to assist this work.

Jamie and a rebellious young Dulcian named Cully were able to use a laser weapon from a war museum to destroy a Quark, whilst others could be easily overcome by blinding them - throwing a cover over their head - or tripping them up - tying a rope round their legs. Clearly they did not have all-round vision.

Later, the Doctor developed an explosive which was used to deplete the Quark force further. Those remaining were called off search-and-destroy work to finish the drilling - the plan being to trigger a volcanic eruption into which an atomic seed capsule would be dropped.

The Doctor was able to slip this capsule onto the Dominator spaceship just before it took off - destroying it along with the remaining Quarks and their Dominator masters.

Played by: John Hicks, Gary Smith, Freddie Wilson. Voiced by: Sheila Grant.

Appearances: The Dominators (1968)

• It was an argument over the commercial exploitation of the Quarks which led to writers Mervyn Haisman and Henry Lincoln finally falling out with the Doctor Who production office, after the BBC had allowed them to feature in TV Comic without consulting them. They had created the robots specifically with the intention of exploiting them financially themselves, having seen what Terry Nation had earned through the Daleks.
• In these comic strips, the Quarks are a fully autonomous force of aggressive invaders, no longer under the control of the Dominators.
• The Quark performers were all schoolboys.
• Voice artist Sheila Grant would later be seen on screen as Jane Leeson in Colony in Space.
• We see two different techniques used for the Quark weapons. The first is when they kill Cully's friends, where the flesh appears to burn and melt momentarily. This sequence was achievable as on film, but in studio the simpler and quicker method of pumping smoke through the victim's costume was used. At one point Cully is wounded by a Quark, but only suffers a temporary paralysis. 
• A Quark featured as one of the cards that came with Weetabix packs as part of their first Doctor Who promotion:

• The replica Quark which featured in the Doctor Who exhibition at Peterborough Museum in 2025:

P is for... Pyroviles

Huge rock-based creatures with a molten magma core, who formed a bridgehead in the Campania region during the height of the Roman Empire, following the loss of their home planet Pyrovilia. They could kill with an incinerating blast from their mouths.

Their intention was to boil away the Earth's oceans and make the planet more habitable for them as a new home. They were susceptible to the cold water, and sufficient quantities could cause their exoskeleton to solidify and shatter.

On first arriving on Earth, they crash-landed their escape capsule and were reduced to dust.

The earthquake of 62AD in the Pompeii area triggered their awakening.

Their dust could infect human beings, causing them to slowly turn to stone themselves after first becoming their mental servants. They had the ability to psychically affect certain individuals with latent abilities in this area. Through a human agent named Lucius Petrus Dextrus who was a powerful local official in the city of Pompeii, they commissioned rock-based circuitry which would help them harness the energies of Mount Vesuvius in order to further their plans. 

The High Priestess of the Sibylline Sisterhood was also infected with their rock dust, and was now almost fully composed of stone.

In order to stop the Pyroviles, the Doctor was forced to trigger the devastating eruption of the volcano in 79AD, knowing it would kill thousands of men, women and children - their deaths being the price to pay to save the entire planet. This was a fixed point in time, which he could not alter.

It would later transpire that Pyrovilia had been taken by Davros to power his Reality Bomb, and the Doctor and Donna Noble were able to return it to its proper place and time.

Appearances: The Fires of Pompeii (2008).

• The design of the adult Pyroviles was based on that of a Roman soldier, whilst that of the Sisterhood priestess was based on the plaster casts of the victims of the volcanic eruption which destroyed Pompeii and Herculaneum.
• If Pyrovilia was put back where it came from, then these Pyroviles would never have fled from it and so come to Earth and tried to conquer it - so there would have been no reason for the Doctor to deliberately trigger the eruption of Vesuvius and destroy Pompeii. As it is historic fact, however, this must surely mean that it was simply a natural disaster.

P is for... Pye, Reginald

Projectionist at the Palazzo Movie Theatre in Miami, Florida, in 1952. He alone had survived the sudden disappearance of 15 audience members during the screening of a Mr Ring-a-Ding cartoon short.

Though the cinema had now been boarded up by the police, the Doctor and Belinda Chandra discovered that Reg remained inside, playing movies to an empty auditorium.

When they broke in, he tried to warn them into leaving. The reason he stayed to run the features was because he was enslaved by Lux, God of Light, who fed on the projections. He had taken on the form of the cartoon character, and sought to gain corporeal form in order to leave this place.

Reg had lost his wife Helen in a car accident a short time ago, though she was preserved on celluloid, captured from his old home movies. Lux threatened to destroy these memories of her if he failed to obey, but would be rewarded by him recreating Helen in 3-D form from the images.

He attempted to help the Doctor and Belinda by running the cartoon, knowing that Lux was compelled to sing along - distracting him long enough to allow them to escape. However, they were caught and turned into celluloid figures themselves. After escaping, Belinda encouraged Reg to help destroy Lux and, inspired by Helen, he agreed - sacrificing himself to set light to the mass of flammable film stock. This blew out one of the walls, which allowed Lux to be swamped by sunlight - eventually drawing him away from Earth towards the sun.

Played by Linus Roache. Appearances: Lux (2025).

• Linus is the son of Coronation Street icon William Roache, who has played the character Ken Barlow in the soap since its very first episode in December 1960.
• Between 1972 and 1975 Linus played Ken Barlow's son Peter in the series, before returning in 2010 as a different character.
• His first big film role was as the conflicted title character in Priest, in 1994, who struggles with his sexuality.
• Genre appearances include Batman Begins (as Bruce Wayne's father) and The Chronicles of Riddick.
• On screen he has played Vincent Van Gogh (Omnibus), Samuel Taylor Coleridge (Pandaemonium) and Robert F Kennedy (in Oliver Stone's JFK).

P is for... Purcell

Jim Purcell was the bullying and obnoxious landlord of Alex and Claire, who lived with their son George in a high rise flat. Purcell lived alone with only bulldog Bernard for company. George was really an alien child who possessed remarkable abilities. Terrified of rejection, he was constantly afraid and could banish the objects of his fears - containing them within an old dolls house in his bedroom cupboard. Purcell represented one of these terrors for the boy, and he found himself suddenly sucked down into his carpet one evening, as though into quicksand. He then found himself in the dolls house where he was attacked by the wooden Peg Dolls which inhabited it. He was transformed into one of the creatures.

Once George overcame his fears, everyone was returned to normal, including Purcell. The experience would hopefully have made him a less unpleasant individual.

Played by: Andrew Tiernan. Appearances: Night Terrors (2011).

• An early film role for Tiernan was as Piers Gaveston in Derek Jarman's 1991 film of Marlowe's Edward II.
• He played doomed astronaut Victor Carroon in 2005's live remake of The Quatermass Experiment.
• Other film roles include 300 and its sequel, Interview with the Vampire and The Pianist, whilst TV appearances include Jonathan Creek, Midsomer Murders, Foyle's War and Dalziel & Pascoe.

P is for... Pting

Diminutive creatures noted for their insatiable appetite for anything inorganic - especially if it provided them with an energy source. They were reputedly indestructible and could survive in the vacuum of space. One of them once wiped out an entire space fleet. They could be rendered immobile for short periods by staser fire, however, but made for extremely difficult targets.

The Doctor and her companions encountered one when it infiltrated a hospital ship, the Tsuranga, carrying them and a number of patients and staff. The creature began eating its way through the ship's infrastructure, aiming for the anti-matter power core. 

An attempt to lure it into an escape pod failed, so the Doctor was forced to devise an alternative scheme. A detonation device was rigged to attract it and it consumed this instead, before being ejected from the vessel through an airlock.

On exploding, the Pting merely absorbed the resulting energy and survived to float away through space.

The Doctor later encountered another member of the species, which she nicknamed "Tiny", on a penal asteroid run by the Judoon.

Appearances: The Tsuranga Conundrum (2018), The Timeless Children (2020), Revolution of the Daleks (2021)

• Though the episode was written by Chris Chibnall, the Pting was actually the creation of writer Tim Price. He had been a member of the writers room for Series 11 but had been unsuccessful in getting a story commissioned. Chibnall liked the alien he had devised, however, and Price agreed he could use it.

P is for... Psi

Psi was one of the people recruited by the Doctor to help rob the Bank of Karabraxos - notorious for its high levels of security. None of the thieves knew that the Doctor was behind this heist - even him, as they had all willingly handled a Memory Worm which wiped their recent memories. This was so that they couldn't reveal anything if captured. The bank employed a creature known as the Teller which could psychically sense guilt.

Each of the gang was promised a reward - something which the bank held in its vaults. Psi had undergone a technological upgrade which allowed him to interface directly with any computerised systems. In doing so, his longer term memories had been removed and stored on a chip, and getting this would be his reward. 

They were also given a suicide device - a ripper - to use in the event that the Teller caught them and destroyed their brains seeking their guilt. After helping to breach the security systems, Psi sacrificed himself by downloading data about various notorious criminals into his mind, which drew the Teller away from the Doctor and Clara. This then allowed them to reach their goal - actually the rescue of the Teller's mate.

It later transpired that the ripper was really a teleport, which took them to the safety of the TARDIS. Psi gained his memory chip, which allowed him to recall his family.

Played by: Jonathan Bailey. Appearances: Time Heist (2014).

• Pretty much everywhere these days, he started off as a child actor with the RSC and also played Gavroche in Les Miserables in the West End. His first significant TV role was as the corruptible local journalist in Chris Chibnall's Broadchurch.
• Period drama Bridgerton really put him on the map, before he moved to the big screen with Wicked and its sequel, and the male lead role in Jurassic World Rebirth.
• He hasn't given up the theatre. I saw him in the title role of Richard II at the Bridge Theatre in London in 2025.
• In 2024 he set up an LGBTQ+ charity - The Shameless Fund.
• Voted sexiest man alive in 2025.

P is for... Programmers

Two of the staff who helped to operate the Game Station - the space station in orbit above Earth formerly known as Satellite Five. They were employees of the Bad Wolf Corporation, responsible for ensuring that the station continually broadcast hundreds of game shows to the inhabitants of the planet below.

Programmer Davitch Pavale noticed irregular activity in one of the Big Brother games, and alerted his female colleague who had noted similar activity in a Weakest Link she was monitoring. This involved a pair of new contestants who were not taking the deadly games seriously. The Doctor and Rose had been abducted and transported into the games - the Doctor into the Big Brother house and Rose into a Weakest Link contest. The situation worsened when the Doctor broke out of his game, taking another contestant, Lynda, with him. When they alerted the Controller, through whom all output from the Game Station was broadcast, she instructed them to take no hostile action.

The Doctor, Lynda and Captain Jack Harkness - who had ended up on What Not To Wear - were captured by security guards but soon escaped and began making their way towards the control room.

Despite the fact that they appeared to be armed, the Controller once again refused to take action against them. 

This was because she was under the control of the Daleks, who had been responsible for bringing the Doctor and his companions here.

The Doctor warned them of an imminent Dalek attack, and the Programmers joined Jack in helping to defend the Station. Both were killed when their weapons proved ineffective against the invaders.

Davitch had carried a torch for his colleague, only letting her know of this before they perished.

Played by: Jo Stone-Fewings (Davitch Pavale), Nisha Nyar. Appearances: Bad Wolf / The Parting of the Ways (2005).

• It would probably be cause for controversy these days but the Female Programmer doesn't merit a name.
• Nisha Nyar has featured on many Big Finish audios.
• She previously played (uncredited) a Kang in Paradise Towers. 
• Jo Stone-Fewings is primarily a theatre actor, having appeared in over a dozen Shakespeare productions, many with the RSC.
• He had previously worked on a Russell T Davies drama - Mine All Mine - in 2003.

P is for... Pritchard

Richard Pritchard was a representative of Vector Petroleum, who controlled a mining complex known as The Drum in the Highlands of Scotland. He was Vice President of Subaquatic Resources, for The Drum was located deep beneath a man-made lake in a flooded valley.

As senior company staff member on the team, he took charge when commander Moran was killed in a freak accident. A capsule of unknown origins had been found on the floor of the lake and brought on board. Its engines fired unexpectedly and Moran was killed. Pritchard was interested mainly in how this apparently alien technology could be exploited by the company. He was especially interested in a missing power cell, which the Doctor had drawn the crew's attention to. 

Despite the appearance of ghostly figures which had begun to haunt the complex - including spectres of Moran and a figure dressed like a funeral director - Pritchard decided to don diving gear and go outside alone to find the power cell. Moran's ghost turned up and killed him, trapping and drowning him in the airlock before he could suit up.

Pritchard then joined the ranks of the ghosts. All were lured into a Faraday Cage where they were trapped by the Doctor, and this was then fired into space where the ghosts - really psychic transmitters - would dissipate over time.

Played by: Steven Robertson. Appearances: Under The Lake / Before The Flood (2015)

• Robertson is best known for his regular role in crime drama Shetland. He was born and raised on the Shetland Islands. 
• He also appeared in supernatural drama Being Human. This was in its fifth series, when he played civil servant Dominic Rook whose government department dealt with supernatural phenomena.

P is for... Pritchard, Mrs

Stern, cold-hearted housekeeper of Gabriel Chase, a gloomy mansion in Perivale. The Doctor and Ace visited here in 1883 when it was in the possession of a man named Josiah Samuel Smith. Pritchard only assumed her role at night, after the day staff had left - unwilling to remain there after dark. Smith lived in the house with his ward Gwendoline, a guest named Redvers Fenn-Cooper, and a butler named Nimrod - identified by the Doctor as a Neanderthal. Fenn-Cooper had been an adventurer who had explored Africa, but now appeared to be mentally unstable.

Mrs Pritchard treated him cruelly and disliked Nimrod, but was kinder towards Gwendoline. She resented Ace's influence over the girl.

Hidden beneath the house was a spaceship belonging to an entity known as Light, which was hibernating after conducting a survey of life throughout the galaxy. It had been contact with Light's energies which had deranged Fenn-Cooper. Nimrod had been a specimen collected by it during its survey. Locked up in the ship was another creature called Control. She and Smith had been agents of Light. One would interact with the environment, allowed to be influenced by it, whilst the other remained behind as an experimental control subject.

Smith had assumed the role of an English gentleman but he sought even greater status - by having Fenn-Cooper assassinate Queen Victoria. 

It transpired that the housekeeper was actually Lady Margaret Pritchard, wife of the house's owner Sir George, and Gwendoline's mother. Smith had killed Sir George and hypnotised his wife and daughter. They recalled their true identity and were reunited, just before Light turned them both to stone to prevent them evolving. 

Played by: Sylvia Syms. Appearances: Ghost Light (1989)

• Syms was a huge star of British cinema throughout the 1950's and '60's, appearing in such classics as Ice Cold In Alex (1958) and Victim (1961). She guested in many TV series in the 1960's including The Saint (multiple times in different roles), The Baron, Danger Man, Paul Temple and The Strange Report. Latterly (she died in 2023) she was a regular in EastEnders.
• William Hartnell played her father in the drama The World Ten Times Over (1963).

P is for... Prisoner Zero

In its natural form, a huge snake-like creature with jagged fangs, it had the ability to shape-shift and take on the appearance of other beings with whom it had formed a psychic link. It derived its name from its captivity by the Atraxi in their maximum security jail. The explosion of the Doctor's TARDIS caused a crack to appear randomly across the universe, and one of these occurred in its cell - linking it to the bedroom on Earth of a girl named Amelia Pond, who lived in the village of Leadworth with her aunt. The Doctor met her there in 1996 as a child when the TARDIS crash-landed in her garden just after he had regenerated.

Prisoner Zero escaped through the crack and lived undetected in Amelia's home for 12 years, concealing itself in a bedroom whose door it hid behind a perception filter.

It was discovered by the Doctor and an adult Amelia - now Amy - in 2008. It had caused several inhabitants of the village to fall into comatose states, using their likenesses to move around unnoticed. When the Doctor opened the crack in the bedroom wall, it alerted the Atraxi to Prisoner Zero's location. They lay siege to the Earth, threatening to destroy it if their captive was not handed over. Prisoner Zero knew that this would mean certain execution.

The creature could not only assume the form of an individual but multiple beings - even of different species. The effort to maintain the illusion was great and it often revealed itself through the appearance of its fangs or by speaking through the wrong body - such as when it impersonated a man and his dog, and a mother with two children.

The Doctor eventually lured the creature to the local hospital, where Amy's fiancé Rory worked as a nurse. Here, the Atraxi recaptured it before they could destroy the Earth. Before it was taken away, it cryptically warned the Doctor to beware "the Silence"...

Voiced by: William Wilde. Played by: Olivia Colman, Edin and Merin Monteath, Marcello Magni.

Appearances: The Eleventh Hour (2010).

• William Wilde had previously played a Draconian captain in Frontier in Space (credited as Bill Wilde).
• Now one of Britain's most popular actors, Colman would go on to win an Academy Award for her portrayal of Queen Anne in The Favourite. 
• She would also play Queen Elizabeth II, in the third and fourth seasons of The Crown.
• She first came to prominence in a number of comedic roles, in Peep Show, Green Wing and the film Hot Fuzz.
• A breakout role was opposite David Tennant in Chris Chibnall's Broadchurch.
• She appears, as herself, in The Five(ish) Doctors Reboot, made for the 50th Anniversary.
• Marcello Magni was the voice of Pingu the Penguin in the CBBC series.

P is for... Primords

When human beings came into physical contact with a strange green slime, released from deep within the Earth's crust, a genetic mutation took place. They reverted to a primordial state - hirsute and savage. With some individuals, the process took time. First the skin would begin to turn green and they would experience a crippling ringing sound in their heads. They would crave increasing levels of heat. 

The Doctor and UNIT encountered these creatures at a drilling project - nicknamed "Inferno" - in central England. Professor Stahlman believed that a gas found only deep underground could be exploited as a new source of cheap energy and he refused to heed scientific advice in his pursuit of it. A technician named Slocum was the first to be infected by the slime, and he became homicidal. Anyone attacked who survived became infected and would begin to mutate. It took multiple bullet wounds to kill a Primord, though they were susceptible to cold temperatures.

Stahlman recklessly handled some of the slime and became infected as well, though he was able to keep the mutation in check for a time due to his obsessive nature.

As the animalistic behaviour took over and they mutated fully, victims felt compelled to make others like themselves as well as kill - deliberately exposing them to the slime. This fate befell the Sergeant Benton from an alternative Earth. Here, the professor's project was much more advanced and the Doctor encountered several fully mutated Primords.

They perished along with the planet - destroyed by the natural forces unleashed by the drilling.

The Doctor was able to return to the normal universe where only one person fully mutated - Professor Stahlman. Stunned by CO2 fire extinguishers, he was shot dead by the Brigadier.

Played by: Olaf Pooley (Stahlman), Walter Randall (Slocum), Derek Ware (Private Wyatt), Ian Fairbairn (Bromley), Dave Carter, Pat Gorman, Walter Henry, Philip Ryan, Peter Thompson. 

Appearances: Inferno (1970)

• The Primords are never named on screen. The name was given to them by producer Barry Letts - derived from "primordial".
• The script suggested ape-like creatures - a devolved version of humanity - but director Douglas Camfield opted to make them more like werewolves.
• Olaf Pooley was resistant to wearing the full Primord make-up.
• Walter Randall was one of Camfield's stock repertory of actors. After playing the priest Tonila in The Aztecs he was El Akir in The Crusade, and then Egyptian warrior Hyksos in The Daleks' Master Plan. He was also an IE guard in The Invasion, and finally one of the human overseers in Planet of the Spiders.
• Ian Fairbairn was another of the Camfield rep company - appearing in The Invasion as Gregory and The Seeds of Doom as Dr Chester. He had earlier played Questa in The Macra Terror.
• Dave Carter was, like Pat Gorman, a regular extra / monster performer in the series. He had already played the Old Silurian in Season 7, as well as a plague-infected ambulance driver in the same story.

P is for... Primitives

The somewhat derogatory name given to the inhabitants of the planet Uxarieus by a group of colonists from 25th Century Earth. Initially hostile to the newcomers, they co-existed uneasily by bartering with each other. Sometimes the Primitives would abduct a colonist and they would have to be ransomed back by providing food. 

They painted their bodies using dyes made from rocks and roots and armed themselves with spears and knives. Their city lay close to the colony, but was in ruins. Most dwelt in a nearby underground complex ruled by a diminutive priestly caste which worshipped a powerful weapon. The Primitives were the devolved survivors of a once great technological civilisation, but now they used pieces of their ancient technology to adorn their bodies.

One Primitive assisted the colony's chief engineer, Jim Holden, who discovered that they had telepathic abilities. Despite this, the Doctor was at one point able to distract one of them with a disappearing coin trick.

A man named Norton turned up one day, claiming to be a survivor of another colony. He said that the Primitives had killed most of his people, who had also come under attack by giant lizards. He murdered Holden and his Primitive assistant before sabotaging the colony's power supply - making it look like the Primitive had attacked Jim first. This was because Norton was really an agent for IMC - the Interplanetary Mining Corporation - which wanted to exploit the planet's rich mineral resources and was prepared to kill to get them.

Found tied up in the ruined city by IMC guards, the Doctor's companion Jo Grant was kidnapped by the Primitives and taken to the underground complex - to be sacrificed to the weapon and its Guardian. The Doctor went to fetch her back.

Later, he was forced to return with the Master who wanted control over the weapon. The Guardian elected to sacrifice itself rather than see the device used for evil. The Doctor tried to save the Primitives and the priests, but without the Guardian to guide them they wandered aimlessly through the complex, and were destroyed when the weapon exploded. Some may have survived on the surface.

Played by: Pat Gorman, Derek Chafer, Les Clark, John McGrath, Stewart Anderson, Emmett Hennessy, Walter Turner, Mike Stephens. Appearances: Colony in Space (1971).

• The actors playing the Primitives are clearly wearing thin body suits, but they are supposed to be naked save for a loincloth. 
• Gorman, who appeared in the series regularly as an extra / monster performer (from The Dalek Invasion of Earth in 1964 to Attack of the Cybermen in 1985) played a colonist and an IMC guard as well as a Primitive in this story.
• A number of stuntmen also portrayed Primitives for action sequences, including Terry Walsh, Alf Joint and Dinny Powell.

P is for... Priests

Diminutive beings who were the corrupted survivors of a super-race which once thrived on the planet Uxarieus. They had developed a weapon capable of destroying whole star systems, but its radiation gradually wrecked the planet's environment and its people retreated into an underground city. 

The civilisation collapsed into superstition and barbarism. Some individuals formed a priest class as they turned their backs on technology and began to worship the weapon and its Guardian - one of their number who controlled it and fed on its energies. The Priests were mute and almost blind due to their subterranean existence, developing telepathic powers instead.

Part of their ritual involved sacrifices to the weapon, by casting their victim into its nuclear furnace. Jo, and later the Doctor and Master, were threatened with this fate.

The Doctor was able to convince the Guardian of the limitless potential for evil which the weapon posed, and it elected to sacrifice itself by self-destructing the device. He tried to help the Priests flee the city but, their telepathic link to the Guardian broken, they simply staggered aimlessly through the complex and were destroyed in the subsequent explosion.

Played by: Stanley Mason, Antonia Moss. Appearances: Colony In Space (1971)

• Mason would return in the very next story, playing Bok in The Daemons.

P is for... Priest Triangles

Crystalline diamond-shaped entities which acted as caretakers in the Temple of Atropos on the planet Time. They carried out routine maintenance and looked after the Mouri - beings who helped control the sentient force of Time itself. They were incapable of carrying out detailed repairs and so awaited the arrival of someone who could fix the damage to the Mouri caused by Swarm and Azure. They mistook Vinder and the Doctor's companion Yaz for maintenance specialists when they were carried to the temple.

Swarm destroyed one of the Triangles and Azure another when it recognised them as agents of Time. 

The Doctor was later approached by a third which enquired if she was the help it awaited.

Voiced by: Nigel Lambert. Appearances: Flux: Once Upon Time (2021)

• Lambert had previously played scientist Hardin in The Leisure Hive. He voiced all three of the Triangles.

P is for... Price, Captain

A UNIT officer in charge of the mobile HQ when the organisation raided the ATMOS factory outside London. This produced a highly efficient catalytic converter for motor vehicles, combined with an integrated GPS system.

Owner Luke Rattigan was a teenage tech genius who had invented a revolutionary new search engine and made his fortune. He was secretly in league with the Sontarans, however, who were going to exploit ATMOS as a weapon against the human race. Rattigan believed the aliens were going to relocate he and his high IQ followers to a new planet.

Captain Marion Price led on co-ordinating the global response to the threat, arranging for a nuclear strike against the Sontaran flagship.

As the aircraft Valiant cleared the toxic air around the ATMOS factory and the battle against the Sontarans turned in UNIT's favour, Price suffered a momentary loss of self-control and kissed her superior officer, Colonel Mace, revealling unstated romantic feelings for him.

Played by: Bridget Hodgson. Appearances: The Sontaran Stratagem / The Poison Sky (2007)

• Spin-off literature has Price later put in command of the Valiant, at the time when it is shot down by the Daleks in The Stolen Earth.
• Film roles for Hodgson, who previously acted under the name Biddy Hodson, include Wilde (2004) and Hellboy (1997). She appears to have left screen acting after Doctor Who.

P is for... Priam

King of of Troy at the time of its decade-long siege by the Greek forces commanded by Agamemnon. A world-weary figure, he was often disappointed and frustrated by his children. Whilst he admired the bravery of eldest son Hector, he despaired of the cowardly and effete Paris - the man who had led to this conflict after running away with Helen, wife of King Menelaus and sister-in-law to Agamemnon.

Daughter Cassandra usually squabbled with Paris, when she wasn't complaining about being disrespected and having her prophesies ignored.

Paris brought the TARDIS into the city, believing it to be a gift from their god Poseidon, and Cassandra naturally denounced it as an evil omen. Priam reluctantly agreed it should be burned - which prompted the Doctor's companion Vicki to emerge from it. Priam took to her, and had her change her name to the more Trojan sounding Cressida.

When it became clear that she knew Steven Taylor - suspected to be a Greek Spy - Priam had her thrown into jail. She had suggested to the Trojans that she also had the gift of prophesy (knowing as she did of future events) and had to prove herself or face being burned as a witch. Priam's youngest son, Troilus, had fallen in love with her in the interim.

The old king allowed himself to be swayed by Paris when a large wooden horse was apparently left behind by the departing Greek army, and had it brought into Troy - another gift from the gods.

The warrior Odysseus was among those hiding inside - along with the Doctor who had reluctantly proposed the plan - and he slew Priam and Paris, and took Cassandra captive.

Played by: Max Adrian. Appearances: The Myth Makers (1965)

• According to myth, Priam had 50 sons and many daughters. He was killed, aged 80, not by Odysseus but by Achilles' son Neoptolemus.
• Oddly, Priam as presented here does not bat an eyelid when favoured son and heir Hector is killed. In Homer's Iliad he is grief-stricken and goes to Achilles to beg for the return of Hector's body.
• Adrian (1903 - 1973) was a regular collaborator with writer Donald Cotton and had performed in a number of his radio productions. Cotton was therefore able to secure his talents for this story.
• It was often claimed that William Hartnell refused to work with Adrian as he was gay and Jewish, but the Doctor and Priam simply never share any scenes together.
• To many in Britain, Adrian is best known for playing patriarch Ludicrus Sextus in Up Pompeii, opposite Frankie Howerd.
• Horror fans will recall him from the vampire segment in Dr Terror's House of Horrors, opposite Donald Sutherland.
• He was a member of the Royal Shakespeare Company, and an original member of the National Theatre, appearing as Polonius in its very first production (Hamlet being played by Peter O'Toole). He played the Dauphin in Olivier's film of Henry V, and Alec Guinness and Olivier read the lessons at his memorial service.

P is for... Preslin

When the TARDIS materialised in Paris in the late 1500's the Doctor decided to seek out some of the noted scientists of the era. One of these was Charles Preslin - an apothecary who lived near Port St Martin.

Preslin had investigated germs but his work had drawn condemnation from the Catholic church, including the Abbot of Amboise. He had previously been accused of heresy for his work. He was preparing to flee Paris when the Doctor visited. They spoke for a time and the Doctor told him of a man in Germany who was working on a device which would allow him to observe the germs he studied.

Steven Taylor later went in search of the Doctor but found Preslin's home empty. He went back there later with Anne Chaplet and this time found the Doctor present. On learning that the date was actually August 1572, the Doctor rushed his companion back to the TARDIS - knowing that the massacre of the Huguenots was about to begin. 

Played by: Eric Chitty. Appearances: The Massacre (1966)

• Chitty (1907 - 1977) would return to the series to play Coordinator Engin in The Deadly Assassin.
• He appeared in over 50 films during his 40 year acting career, as well as a great many television programmes.

P is for... President

The UK in the 2000's in a parallel universe was governed by a President rather than a Prime Minister. He was approached by the industrialist John Lumic to approve a new project. This entailed the preservation of the human mind when threatened by death or debilitating illness by transplanting the brain into a new artificial body. Lumic had been perfecting the process in South America, but wished it to be adopted in his homeland. He had a personal stake in this as he was suffering from a terminal illness which had already confined him to a wheelchair with a built-in life-support system. The President met with him and one of his employees - Pete Tyler - onboard his personal airship.

As he suspected, the President rejected the project on ethical grounds - but Lumic had planned to carry on regardless. Tyler's wife Jackie was hosting a birthday party that evening, and the President would be in attendance. Lumic had already carried out a number of transplants, using the conditioned brains of homeless people. In their new armoured bodies these were known as Cybermen.

The Cybermen raided the Tyler mansion during the party. When the President challenged Lumic through one of them, much against the Doctor's advice, he was electrocuted by it.

Played by: Don Warrington. Appearances: Rise of the Cybermen (2006).

• Warrington first came to fame as boarding house lodger Philip in ITV sitcom Rising Damp. This ran between 1974 - 1978, and spawned a cinema outing.
• These days he is better known for playing Police Commissioner Selwyn Patterson in Death in Paradise.
• He was made an MBE in 2008. 
• He took part in Strictly Come Dancing the same year, getting knocked out after three rounds.
• Warrington voiced the Time Lord Rassilon for Big Finish.

P is for... Prentis

A funeral director who was a member of the cowardly Tivolian race. He visited a remote part of Scotland in 1980, transporting the body of the Fisher King for burial there. The Fisher King had conquered Tivoli before finally being overthrown and killed by another invader. However, the creature wasn't dead at all, and had prepared a rescue scheme. A mental message was implanted into people's minds, which caused them to turn into ghostly psychic transmitters after they died. This would summon his supporters to find an free him.

Prentis was the first to die, and his phantom image haunted the Drum 129 years later. This was an underwater mining complex situated at the bottom of the lake which later flooded the valley where his hearse had landed.

All of the "ghosts" were trapped by the Doctor in a Faraday Cage, which UNIT had launched into space where their psychic energy would eventually dissipate.

Played by: Paul Kaye. Appearances: Under the Lake / Before the Flood (2015).

• Writer Toby Whithouse first created the Tivolians for The God Complex, where Gibbis was played by David Walliams.
• Kaye first came to fame by playing the celebrity interviewer Dennis Pennis in The Sunday Show (1995 - 97). 
• His acting credits include roles in Game of Thrones and Jonathan Strange & Mr Norrell.
• An early job as a graphic designer involved designing merchandise for a number of football clubs, including Tottenham Hotspur.

P is for... Prem

Prem was the first husband of Yasmin Khan's grandmother Umbreen. They were married in August 1947 in the Punjab - just as the arrangements for the partition of India were being finalised. This saw the creation of Pakistan as the country divided along religious lines. Prem was Hindu, but was marrying a Muslim. His brother Manish zealously supported the Hindu cause, and had already murdered the man who was to have officiated at the wedding. The Doctor stepped in to conduct the ceremony herself. 

Manish killed Prem soon after, believing him a traitor to their faith.

Played by: Shane Zaza. Appearances: Demons of the Punjab (2018)

• Zaza is primarily a theatre performer, but made a rare film appearance in The Da Vinci Code.