Elisabeth Sladen

Elisabeth Sladen, who played one of the most popular Doctor Who companions in the franchise's history, has died. She was 63.

"It is with much sadness that we can announce Elisabeth Sladen, the much-loved actress best known for her role as Sarah Jane Smith in Doctor Who and CBBC's The Sarah Jane Adventures, passed away this morning," a BBC spokesman said Tuesday.

Doctor Who gets a return date

As  Sarah Jane Smith on the long-running British sci fi series, she was the companion to the third and fourth Doctor incarnations (portrayed by Jon Pertwee and Tom Baker). Later, her character returned to the revived franchise with the 10th Doctor, David Tennant. Sarah Jane was then spun off into her own children's series, The Sarah Jane Adventures.

"I absolutely loved Lis," Sarah Jane Adventures creator Russell T. Davies said. "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 is survived by her husband Brian Miller and daughter Sadie.

Check out this tribute to Sladen as Sarah Jane Smith: