Doctor Who actress Elisabeth Sladen has died at the age of 63, the BBC has confirmed.
She joined the programme in 1973 and became one of the most popular companions in her role as Sarah Jane Smith. In 2007 she was given her own spin-off series, The Sarah Jane Adventures, which introduced her to a new generation of fans.
Tributes have been pouring in for the Liverpool-born actress, known to her friends and family as Lis.
Russell T Davies, creator of The Sarah Jane Adventures, which won this year's RTS Award for best children's drama, said all those involved in the series had been left "reeling" at news of her death.
He said: "I absolutely loved Lis. She was funny and cheeky and clever and just simply wonderful. The universe was lucky to have Sarah Jane Smith; the world was lucky to have Lis."
Sladen starred in Doctor Who alongside Jon Pertwee, the third doctor, and his successor Tom Baker.
She then returned to the series on a number of occasions over the years before her own CBBC show was created, in which she starred as an investigative journalist trying to defend Earth from extraterrestrial threats.
It had not been widely known that she had been suffering from cancer. She died yesterday leaving behind her husband, actor Brian Miller, and daughter Sadie.
Doctor Who lead writer and executive producer Steven Moffat said she was a "ferociously talented actress".
He said: "'Never meet your heroes', wise people say. They weren’t thinking of Lis Sladen.
"Sarah Jane Smith was everybody’s hero when I was younger, and as brave and funny and brilliant as people only ever are in stories.
"But many years later when I met the real Sarah Jane - Lis Sladen herself - she was exactly as any child ever have wanted her to be. Kind and gentle and clever and a ferociously talented actress, of course, but in that perfectly English unassuming way.
"There are a blessed few who can carry a whole television show on their talent and charisma - but I can’t think of one other who’s done it quite so politely."
CBBC controller Damian Kavanagh said: "I’m deeply saddened and shocked by the news of Lis's untimely death. Lis brought joy, excitement and a sense of wonder to her many fans in her role as Sarah Jane Smith. She was adored by our young audience and I know all of them will miss her as much as I will."
The director of BBC Wales, which makes the Sarah Jane Adventures, now in its fourth series, said the programme could not have been made without Sladen.
Keith Jones said: "The Sarah Jane Adventures has been one of the most successful children's programmes on television in recent years - and without Elisabeth Sladen it would not have happened."
Sladen had spoken of her excitement at being involved in Doctor Who and the Sarah Jane Adventures in a BBC online interview.
She said of her early days as Sarah Jane: "I hit a lovely time in the series. I hit the time of Pertwee and Baker, and sometimes you can almost taste when something is really working.
"And maybe Sarah was the kind of character that they needed at that time. So she took on the companion that had to be for the series and the companion that they wanted."
On the success of her children’s television series, she said: "When you’re filming you’re in a bubble and you do your work and quite often you forget that people are going to see it later.
"It’s quite a shock sometimes. I had no idea the response was going to be this huge. It is an incredible thing that Russell has done to bring this character back to such enjoyment for the viewers. It’s such a great standard to set and we are all so pleased to be part of that."
PA