The Cult Of... Blake's Seven (BBC4): Paul Darrow thought it was The Magnificent Seven in space. Co-star Michael Keaton was told it was The Dirty Dozen in space. Yet a third view was this was Robin Hood in space.

I suppose that's one way of saying that Blake's Seven wasn't very original, borrowing ideas from all over the place.

The main influence must have been Star Wars, in which the rebel alliance battled the Empire. A year later Blake's Seven debuted on BBC1 with another Them Vs Us scenario.

The Cult Of... revisited the series with the aid of its stars, writers and production team. It appears that the Liberator, the spacecraft commandeered by rebel Roj Blake and his merry men (and women), wasn't always a happy ship.

Gareth Thomas, who played Blake, was the first to jump ship. The programme said the makers wanted "a leading man with charisma to spare" and found the ideal person in Royal Shakespeare Company actor Thomas. He thought it would pay the mortgage and put his face on TV in his first starring role.

Halfway through the second series, he told us, he was unhappy to see the show moving from science fiction to fantasy.

Script editor Chris Boucher thought other reasons might have influenced him. "Some pretentious actors with whom he was associated asked him at some stage why he was doing this rubbish, and it got to him," he said.

Whatever the reason, Thomas quit, closely followed by co-star Sally Knyvette who saw her character, Jenna, becoming little more than a clothes horse and sex symbol.

The departure of the title character didn't affect the show. If anything, it developed an even bigger cult following. So much for the leading man's charisma.

He did agree to return for the final episode in which Blake was killed. I suspect Boucher had fun devising a particularly gruesome end for this difficult leading man.

Anyway, many of us preferred the other characters, particularly Servalan as played by Jacqueline Pearce. She was the Federation supreme commander who pursued Blake and the outlaws. Originally, the character was only going to be in one episode but proved popular enough to make a regular.

"Some people said she was a psychopath, but she was the girl next door, depending where you lived," said Pearce.

The costume department wanted to dress her in a safari suit, jackboots and helmet. Pearce resisted, suggesting going the other way and making her incredibly feminine. The result was a truly evil woman who spent her time running around in a ballgown and high heels with cropped hair.

Servalan had a profound effect on many male viewers as Pearce found out. "It was discovering I was a masturbatory fantasy for an entire generation of men - that made a girl feel good," she said.