10 things you didn't know about Doctor Who

5: Tom’s troubles

He may have played the Doctor the longest, but Tom Baker had a pretty rough time of it during his tenure. Just before shooting one of the seasons, he was mauled by a dog and his lip was temporarily disfigured – meaning they had to work the wound into the show by having him bang his face on the TARDIS console in The Pirate Planet.

Later on, Tom suffered a mystery illness that left him skinny and lethargic – and even led to his famously curly hair going straight. As his unruly locks were part of the Fourth Doctor’s image, he had to have his hair permed for the show each day!

6: The hitchhikers guide to the Tardis?

The late, great Douglas Adams was a Doctor Who writer for a time, and in fact penned City of Death, widely regarded as the greatest Who story of all.

Featuring Tom Baker at his most Tom Bakerish ("I say, what a wonderful butler, he’s so violent!"), the story is sublimely funny – which is a surprise as the author of Hitchhiker’s Guide to the Galaxy had serious trouble with it.

Famously prone to writer’s block, Douglas Adams had to be locked into his flat by script editor Graham Williams, who plied Adams with black coffee until the script was sweatily rattled off in a mere weekend. And what a script it was.