E is for... ed-Din, Haroun

A citizen of the town of Lydda in Palestine, at the time of the Third Crusade. He discovered that the sadistic Emir El Akir coveted his daughter Maimuna, but refused to hand her over. One day, however, whilst he was away from home, El Akir raided his house. His wife and son were killed, and Maimuna was abducted. Haroun was left alone with his youngest daughter Safiya, who was not told about the death of her mother and brother. Haroun rescued Barbara Wright from the Emir's men, and gave her refuge in his home. When he had to go out, he gave Barbara his knife - claiming that he would rather she killed the girl than let her fall into El Akir's hands. After Barbara had been recaptured by El Akir, Haroun broke his palace and killed him, whilst Ian and Barbara helped to free Maimuna.

Played by: George Little. Appearances: The Crusade (1965).

• Little went on to become a regular on the ITV soap Emmerdale, playing the Rev. Edward Ruskin for 20 years.

E is for... Eckersley

A mining engineer from Earth who was stationed on the planet of Peladon. His job was to improve the trisilicate mining operations. This mineral was needed by the Federation as part of its war with Galaxy 5. Eckersley set up a new refinery, and wanted to introduce advanced technology to increase production, but found that the local miners were suspicious of this - fearing that it would offend their deity Aggedor. This sacred beast had begun to appear in the mines, killing people. Eckersley witnessed its destruction of his colleague Vega Nexos. When the miners went into open revolt, Eckersley talked ambassador Alpha Centauri into summoning help from the Federation - leading to the arrival of an Ice Warrior contingent under the leadership of Commander Azaxyr. Eckersley maintained that local politics were not his concern, and that he just wanted to get on with his work.
However, it later transpired that Eckersley was in league with Azaxyr to gain the planet's trisilicate for Galaxy 5. Within the refinery he had set up a heat ray weapon, coupled with a holographic projection of a statue of Aggedor, to stage the attacks in the mines. When the Ice Warriors were overpowered and their scheme exposed, Eckersley attempted to flee - taking Queen Thalira as his hostage. The Doctor used the real Aggedor to track them down. The sacred beast killed him, but not before he had mortally wounded it.

Played by: Donald Gee. Appearances: The Monster of Peladon (1974).

• Gee had previously played Major Warne in The Space Pirates.

E is for... Eaters of Light

Savage reptilian quadrupeds with bio-luminescent tendrils, which existed in a pocket dimension of space / time. They swarmed there, but would use portals to other dimensions to visit planets where they could feed by absorbing light. As light made them stronger, so they would become weaker at night. One of the creatures came through a portal in the Highlands of Scotland in the 2nd Century AD, where it attacked and destroyed an entire Roman Legion. The Pictish locals had known of the portal for many centuries and a gate-keeper was entrusted to prevent the creatures from getting through. The present keeper - a girl named Kar - had deliberately allowed this one through the portal so that it could kill the Roman invaders, but it was now a danger to her own people. The gate-keepers employed a special kind of glass and when light passed through this it could hold the creatures at bay. The Doctor organised for the creature to be forced back through the portal, where he intended to hold the rest of its kind back. Minutes in their dimension translated to years in our timescale. Kar and some young survivors of the Roman Legion took his place.

Appearances: The Eaters of Light (2017).

E is for... Earthling

An unnamed Englishman, abducted from Earth around 1980 by General Grugger and his Gaztak mercenaries. They were acting on the orders of the alien Meglos, who required a humanoid body to act as a template in order for him to take on the Doctor's form. Meglos at first resembled a green-skinned version of the Earthling, with cactus-like spines growing from his skin, before settling on the appearance of the Doctor. The process was unstable, however, and the Earthling occasionally asserted himself as he tried to break free. He was released when Meglos reverted to his natural plant-like form. The Doctor and Romana took him to the planet Tigella after Meglos' world of Zolfa-Thura had been destroyed. From there they would return him to the Earth - the Doctor claiming he could get him home five minutes before he left.

Played by: Christopher Owen. Appearances: Meglos (1980).

• The novelisation - not by the story's writers - gives his name as George Morris.

E is for... Earth President

In the year 2540, she was the President of Earth's galactic empire. Her term of office coincided with increased tensions between Earth and its neighbouring rival - the Draconian Empire. It was reported that Draconian ships had begun raiding Earth cargo vessels near the border between the two empires. Matters were not helped when her hawkish military adviser, General Williams, threatened to undermine her. She wanted to see a diplomatic settlement, whilst Williams favoured a military response. She personally questioned the two captured Draconian spies - the Doctor and Jo Grant. With her political opponents clamouring for war, the President reluctantly agreed to cutting off diplomatic relations with Draconia, but refused to start a fresh war between the two empires.
The Doctor and the Draconian Crown Prince finally succeeded in convincing her, and Williams, that a third party was attempting to orchestrate a war - the Master and his Ogron underlings. She gave her blessing for an expedition to travel to the Ogron planet to get proof.

Played by: Vera Fusek. Appearances: Frontier in Space (1973).

• The character remains unnamed on screen and in the novelisation. The book gives some backstory - a love affair between her and Williams when they were younger, and that she only made him her aide as he had been opposed to her election.

E is for... Earp, Wyatt

Marshal of the town of Tombstone in Arizona. He discovered the Doctor and his companions acting suspiciously in a livery stable. They pretended to be travelling entertainers. Earp was friends with Doc Holliday, who had just opened a dentist practice in the town. He discovered that the Clanton family were planning to kill Holliday, but had mistaken the Doctor for the gunslinger. To help protect his friend, Earp went along with this case of mistaken identity - putting the Doctor and his friends in danger. When the Clantons captured Steven and threatened to lynch him, Earp and his friend Bat Masterson saved him, arresting Phineas Clanton and throwing him in jail. Earp was then joined by his brothers Virgil and Warren. The latter was killed when the other Clanton brothers arrived to free Phineas. Earp then joined Virgil and Holliday to confront the Clantons and their ally Johnny Ringo, killing them all at the gunfight at the town's OK Corral.

Played by: John Alderson. Appearances: The Gunfighters (1966).

• Alderson was already a veteran of TV westerns when he came to this, having appeared in series such as Gunsmoke, Maverick and Bonanza. His final film role, before his death in 2006 at the age of 90, was in a western - Young Guns II.
• The real Wyatt Earp was only Deputy Marshal of Tombstone. He died in 1929. As well as a number of law enforcement roles (some of which he obtained through bribery) he also ran a saloon and a brothel, and worked as a miner. He also became a boxing referee, but his reputation as a gambler led to allegations of match fixing.

Inspirations - Colony In Space

Written by Malcolm Hulke, Colony In Space, sees the Doctor visit an alien planet for the first time since his exile to Earth began at the conclusion of The War Games.
You'll recall that the exile scenario was inherited by producer Barry Letts. He and script editor Terrance Dicks could see how this limited their story-telling possibilities, and so resolved to find a way for the Doctor to get back into outer space at the earliest opportunity. But how to do it? An experiment with the TARDIS had sent the Doctor off to a parallel universe at the end of the previous season, but this trick couldn't be played every time.
Dicks had co-written the Doctor's trial, with Hulke, and he knew that one of the reasons he had been exiled was because he tended to get involved - whereas the Time Lords refrained from interference.
Was it that they never interfered, as a point of principle, or was it that they did not like to be seen to do it? The idea then formed that the Time Lords would occasionally get involved in the affairs of other planets - but only through some other agency. With the Doctor excluded from Time Lord society, he could be deemed a free agent. The Time Lords could send him on the odd mission - directing his TARDIS by remote control. For the first of these special missions, the problem would be one that directly impacted on the Time Lords themselves.
They have been seen as powerful and secure enough for other civilisations to entrust them with their secrets. That trust in their abilities would be seriously undermined if someone unscrupulous were to steal these secrets and attempt to use them for their own gain - especially if that someone was one of their own kind.
The story opens with what we can assume to be members of the High Council of Time Lords discovering that one of their files has been stolen by the Master. With the benefit of hindsight, this might well be the Celestial Intervention Agency. They need to get this file back - or at least stop the Master getting his hands on whatever secret the file relates to.

Meanwhile, at UNIT HQ, the Doctor thinks he has fixed the dematerialisation circuit. We have already been told that the Master is going to be involved, and at UNIT the Brigadier thinks that he may have a lead to his whereabouts. The Doctor states that a previous sighting proved to be the Spanish Ambassador. This is an in-joke, as Roger Delgado played the recurring role of the Spanish Ambassador, Count Bernardino de Mendoza, in the 1961 ITC series Sir Francis Drake.
Jo follows the Doctor into the TARDIS, and here we hit a bit of a problem. It is clear that Jo has never been inside the ship before, and does not believe that it can travel in Time and Space.
So, at no point since Terror of the Autons has she been invited in, or taken a sneaky peak when the doors were open. Bear in mind that one school of thought holds that a whole year passed between Terror and The Mind of Evil. Jo has also seen the TARDIS dematerialise - in just the last episode.
There is also the issue of why the Master was messing about with the Axons when he could get his hands on the most powerful weapon in the universe.
This has led some fans to consider swapping the running order - placing this story before The Claws of Axos. I've watched it like this and it works - the only slight hiccup being the Doctor stating that the Master will "have left Earth by now" at the beginning of Claws - implying there's just been an Earthbound encounter.
The TARDIS suddenly comes to life, and the Doctor urges Jo to leave, but she remains and the ship departs.

The idea that the Time Lords have a devious streak starts with this story. Not only are they breaking their own laws by using an agent to intervene on another planet, but they decide not to actually tell him anything about where he is being sent, or why. You would think a successful mission should begin with a comprehensive briefing. Perhaps the Time Lords have been observing the Doctor's travels for quite some considerable time before finally reeling him in, and have realised that he works best when confronted by a mystery - forcing him to think on his feet.
The TARDIS lands on the desolate-looking planet of Uxarieus, and here a number of inspirations can be felt.
Initially the Doctor and Jo encounter a party of colonists who have fled from an overcrowded and polluted Earth to begin a new life as farmers. This is the first time since Planet of Giants that the series has attempted to consider ecological issues. We're still a couple of years away from the BBC sitcom The Good Life (it began in 1975), but concern about the environment and the desire to lead a greener, more simple and self-sustaining lifestyle had been growing since the mid-1960's. This was a reaction to the aggressive marketing of consumerism. If you wanted something new - and you were always being told you needed something new - then it was easy enough to throw out the old one and buy the latest model. Products were being manufactured with an in-built obsolescence. Towns and cities were struggling to cope with the amount of rubbish that was being thrown away, whilst TV screens showed adverts about keeping the countryside tidy. The "Keep Britain Tidy" campaign - still going strong - developed out of the British Women's Institute in 1955, designed to keep the country litter-free.
At this stage in the series, Jo is still a little nice-but-dim - thinking that the colonists left Earth in a spaceship in 1972. Mind you, Hulke will later create a group of people, who really ought to have known better, who will believe such a voyage feasible in 1974.

The colonists have found that the soil will not support their crops, and their venture may be doomed to fail. Added to this, they have now found themselves under attack from some previously undiscovered savage dinosaur creature. This proves to be fakery, created using a holographic projection of an ordinary iguana, coupled with a mining robot equipped with false claws. The people behind this are IMC - the Interplanetary Mining Corporation. They represent polluting Big Business.
For Hulke, they are the bad guys, and he clearly favours the simple farmers. This reflects his strongly felt political views. He was a card carrying member of the Communist Party of Great Britain, though he fell foul of the organisation when they suspected him of spying on their activities for the authorities. He had called the Home Office from the CPGB's offices on a personal matter - relating to his naturalisation papers - and this had been noted on the phone bill. He left the party in the 1950's, possibly due to his objections to Moscow's invasion of Hungary, but retained strong left wing beliefs.

The planet on which these two sides confront each other is not uninhabited, however. which leads us to see another inspiration lurking beneath the surface. The "Primitives" can be seen as a parallel for the indigenous peoples of North America, or indeed any country which has suffered under Western colonialism. The actual plot for much of the story plays out like a Western, with the natives (Green , rather than Red Indians, to use the parlance of the early 1970's) being forced off their land by settlers, who then come under attack by well-organised claim-jumpers. We have a number of shoot-outs between the settlers and the miners as they jockey for supremacy. The IMC commander - Dent - decides to permit an Adjudicator to be called in to determine who should get the rights to this planet. In the earliest days of the judicial court system, smaller towns and villages did not have their own local legal representatives. Justice tended to be meted out by whoever owned the most land in the district. The concept of assizes and circuit judges was created. Prisoners awaiting trial languished in jail until the circuit came round, roughly four times a year.

When the Adjudicator does turn up, rather quickly one might add, it turns out to be the Master in disguise. Viewers watching this story when first broadcast, an episode a week, might just have forgotten that the Master was the one who triggered the Doctor's mission in the first place, and so his turning up was supposed to come as a surprise. At least we have gone a few episodes without him.
Once the Master has arrived on Uxarieus, the reason for the Doctor's mission can come to the fore. The colonists and miners are still fighting each other in the background, but we now learn that the Master is interested in the city of the Primitives.  The Doctor has already been there, after Jo was captured by the Primitives, and he knows that there was once a great civilisation on this planet, which decayed. The elders of the city, possibly a different species to the Primitives, have reverted to superstition - carrying out human sacrifices to their technology. One of the civilisation's leaders still exists - the diminutive Guardian.
This takes us into Erich Von Daniken territory. He is the most famous proponent of the Ancient Astronauts theory, wherein many of the great monuments of prehistory can only be explained by the intervention of visitors from another planet. There will be a lot of this through the course of 1970's Doctor Who. We'll take a closer look at it when we get to Death to the Daleks, where it is more explicitly referenced.

The secret which the Master gained from the stolen file concerns a terrifying weapon - which we'll call the Doomsday Weapon, as that is the title under which this story was novelised. Apparently the Crab Nebula was created when the device was tested. This astronomical phenomenon was first spotted by the Chinese around 1054, when they witnessed what we now know to have been a supernova. This allows us to see that the Guardian's civilisation was at its peak 1400 years before the events of this story.
That's 1400 years in which the Master could have come along and gained the device for himself, instead of waiting until there were two lots of squabbling humans in the way to complicate matters. Why didn't he just turn up a couple of years earlier? Doesn't he have a time machine?
If the Master can be relied upon to suddenly change his plans on a whim, then the Guardian can trump him. He's been guarding the weapon for centuries, but after a brief chat with the Doctor, and one look at the Master, he suddenly decides to commit suicide and self destruct the weapon - blowing up all his own people while he's at it.
It was radiation from the device which was preventing the colonists' crops from growing, and the Doctor seems to think that all that radiation will disappear overnight now that it's gone.
IMC have been overpowered by the settlers, and there is a proper Adjudicator on the way. Now, the reason Dent was happy to call one in in the first place might imply that they tend to side with Big Business, or be open to corruption, so what makes the colonists think that the real one will be any different?
What happens next doesn't concern the Doctor, as he and Jo get back into the TARDIS and return to UNIT HQ, landing just seconds after they left. Good job the TARDIS materialised in the opposite corner of the lab from where it started, otherwise the ship would have landed on top of the Brigadier. (It's only since 2005 that we see that the ship materialises around people and objects).
Next time: The Devil rides out in a quaint English village, which someone had the foresight to name after him. Can you guess who the new vicar of Devil's End might possibly be...?