J is for... Jagaroth

The Jagaroth were an extremely ancient race who wiped themselves out in a terrible war. They were bipedal creatures, with a single eye in the centre of their forehead, and with a mass or worm-like tendrils covering their bodies. Their spacecraft were spider-like black spheres, with support struts which could be retracted up towards the body of the craft. One of the last surviving Jagaroth spaceships landed on prehistoric Earth. The crew attempted to repair it but were unsuccessful. On lift-off, against the judgement of the captain, the ship exploded. The captain - Scaroth - was in a control cabin on the side of the craft. The blast caused a temporal disturbance, which resulted in Scaroth being splintered in time. Twelve identical aspects of him were scattered through Earth's history - leading separate, but psychically linked, lives. Each had one goal - to work towards the survival of their race by influencing human development, so that the Scaroth furthest into the future would have the capability of travelling back through time to stop the spaceship from attempting lift-off - for the Jagaroth race ended with the destruction of the ship.

Donning a human disguise, Scaroth caused the heavens to be mapped, fire to be discovered, and the wheel invented. He was behind the building of the Egyptian pyramids. In the guise of Count Scarlioni, in 16th Century Italy, he also employed Leonardo da Vinci to pint multiple copies of his painting which wold come to be known as the "Mona Lisa".

The twelfth and final splinter of Scaroth adopted the persona of the Count Scarlioni, who resided in a lavish Parisian town house in 1979. 

Here he set Professor Kerensky to work building the machine that would enable him to travel back to prehistory and stop his spaceship from taking off. To pay for the equipment needed, he sold off various art treasures which his earlier personas had left for him, as well as planning the theft of the "Mona Lisa" from the Louvre. He would sell this, and all the copies Leonardo painted, which have been left bricked up in his cellars.

The Doctor's companion Romana was forced to help him complete his device - not realising that it was vital to human history that the Jagaroth spaceship blew up. The Doctor had realised that it was radiation from this explosion which had given life to the primordial seas, which ultimately led to life developing on Earth. Romana and a private detective named Duggan travelled back 400 million years with the Doctor to stop Scaroth reaching and warning his ship. Duggan knocked Scaroth out with  punch and the craft exploded. The last of the Jagaroth was thrown back through time to 1979. The Count's servant, Herman, failed to recognise him without his disguise and caused an explosion in the laboratory which killed them both.

Played by: Julian Glover. Appearances: City of Death (1979).

• Glover had previously appeared in the series in 1965 as King Richard I.
• He's one of that select group of Doctor Who actors who have appeared in the series more than once - and who have also played Imperial Officers in the Star Wars movies.
• He has also been a Bond villain, and an Indiana Jones villain.
• Peter Halliday (who plays an Italian soldier in this story) and Tom Chadbon (Duggan) both provided Jagaroth voices in the opening prehistoric Earth sequence.