It is with great sadness that we report the death of the actress- forever known to us as the Doctor's best friend,Born in Liverpool in February 1946, Elisabeth Sladen took an interest in acting from an early age; she joined the Liverpool Playhouse repertory company as assistant stage manager after drama school, where she would meet her future husband. After a stint touring the country in repertory, she settled in Manchester, during which she had her breakthrough television role in 1970, appearing as Anita Reynolds in. More small roles were to follow in popular shows likeandThen in 1973 came what would be her defining role as she was cast as the replacement companion for third Doctor. Following in the footsteps of popular companion Jo Grant played by, Sladen was to hit the ground running as investigative journalistin her debut story, and over the next three years would see her popularity soar as she became part of what is arguably known as the "golden years" ofalongside fourth Doctor, an era including the story frequently appearing top of fan polls,Despite choosing to leave the programme in 1976, with an emotional departure scene at the conclusion of the serial, Sladen later stated in interviews that although she had left Sarah Jane,. Although she declined producer's offer to come back as support for the Fourth Doctor's regeneration (being present at his own arrival at the end of this week's DVD release), she did returned to the role for the 1981 pilot: having been described by the Doctor as his best friend, Sarah was form her second long-lasting partnership with his "second-best friend" in the titular K9 and Company Sladen was re-united with "her" Doctor, Jon Pertwee, in the 1983 20th anniversary celebration, and again during the 1990s for the two radio storiesand, written and produced by the person who originally cast her,- the two would also be joined by another popular Doctor Who legend in the form ofas the Brigadier.Outside of Doctor Who, Elisabeth continued to work in theatre and television, often alongside her husband Brian; roles included Josie Hall in, a small role in the film, and as Lady Flimnap in a production ofby her former producer Barry Letts, followed a few years later in his production ofas the Cheshire Cat. However, with the birth of her daughterin 1985, she was to focus more on her family.However, Sarah would never be far from her life, with the actress continuing to be a popular guest at Doctor Who conventions, and also featuring in a series of audio adventures from. Then, in 2005, a discussion with the revived Doctor Who's head writer and long-term fan of hers,, led to a guest appearance in the second series adventure, which re-united Sarah (and K9!) with the Doctor in his most recent incarnation () - her appearance proved instrumental in cementing the connection between the 20th and 21st Century productions in a way that the Daleks couldn't!The character, and Sladen's performance, proved to be as popular as ever, if not more so, and led to her own starring role in spin-off series,; theseries continued on from her re-introduction inas an independent investigator of alien activity - now joined by her young own assistants as well as her faithful K9 - and winning a whole new legion of fans, both young and old. It is also a testament to the strength of the show that it has been graced by the appearance of the both the Brigadier (), and the Doctor himself in both his Tenth incarnation in(and's final performance as the Doctor), and Eleventh in the form ofin- where Sladen was also to come 'full circle' by performing with the actress she 'replaced' way back in 1973,, aka Jo Jones né Grant.The series itself has gone on to win awards, including theaward forAt the time of her death there are still three stories ofto be broadcast on television, and her autobiography, Who's That Girl is due out later in the year.