Image caption John's Liz Shaw was Jon Pertwee's first assistant during his time as Doctor Who

British actress Caroline John, known to many for playing Doctor Who companion Liz Shaw, has died at the age of 71.

A funeral was held in south-west London on Wednesday for the Yorkshire-born actress, who starred opposite Jon Pertwee's Doctor in the BBC series.

John played Liz Shaw in four Doctor Who adventures in 1970, later reprising her role in 1983's The Five Doctors.

Doctor Who chief writer Steven Moffat paid tribute to "a brilliant actress" and "tremendous co-star" for Pertwee.

He said Liz Shaw was "not just a sidekick but a scientist in her own right and a match for the universe's number one know-all".

For the first time, the Doctor had an assistant who was basically an equal and he treated her as an equal Peter Ware, Doctor Who Magazine

"The Doctor's companions should never be his assistants - they're the people who keep him on his toes and that's what Caroline did."

After training at the Central School of Speech and Drama, John spent four years with the National Theatre Company under artistic director Sir Laurence Olivier.

Among her stage credits were Much Ado About Nothing, Rosecrantz and Guildenstern are Dead and as an understudy to Dame Maggie Smith in the role of Desdemona in Othello.

As Elizabeth "Liz" Shaw, John made her first appearance alongside the newly-regenerated third Doctor in the story Spearhead from Space.

Her character witnessed the reawakening of an ancient race in The Silurians and stopped an insane scientist from cracking open the Earth's crust in Inferno.

She also got to drive Bessie, the Doctor's canary yellow roadster, despite the actress not having a driving licence at the time.

Doctor Who Magazine assistant editor Peter Ware told the BBC News website that John's character was "a very different type of companion than any that had come before".

"For the first time, the Doctor had an assistant who was basically an equal and he treated her as an equal," he added.

"Intelligent, beautiful, her character was a genius and in real life she was intelligent and beautiful too."

She was a brilliant actress and a lovely, kind soul who was a joy to be around and who was interested in everyone David Richardson, Big Finish Productions

He said that, from the 1990s onwards, John had made regular appearances at fans' conventions where she was "very kind, very warm and very generous".

"She only stayed with the show for one year but was very fondly remembered by the fans," he said.

Both John and husband Geoffrey Beevers went on to work on several Doctor Who audio and straight-to-video spin-offs.

"Carry was always delighted to return to Liz Shaw and reprised the role several times in our audio series," said David Richardson of production company Big Finish.

"She was a brilliant actress and a lovely, kind soul who was a joy to be around and who was interested in everyone. She will be greatly missed."

In recent years, she was seen in episodes of Doctors, Midsomer Murders and Silent Witness.

She also appeared in an episode of Poirot, alongside husband Geoffrey, playing a husband and wife.

In later years she performed Nightingale, a one-woman show written by her lifelong friend Lynne Redgrave, and toured with Timothy West in the The Master Builder with the English Touring Theatre.