Rose is a quick-witted, inquisitive and independent young woman who finds it easy to adapt to the strange events she's thrown into - but she can become quite emotional.
At the end of series two, Rose and the Doctor shared a tearful farewell as she was transported into a parallel universe.
As she departed, Rose told the Doctor she loved him but he didn't get the chance to reply. With Rose gone, the Doctor often becomes depressed when he's reminded of her.
Rose returns to help the Doctor in episode 11 of series four - will the Doctor be able to admit how he feels?
Born in Swindon in 1982, Billie Piper first came to prominence as a pop star in 1998 when, at just 15, she became the youngest artist ever to debut at No 1 in the UK singles chart with Because We Want To.
In 2003, Billie turned her back on the pop scene to concentrate on her first love, acting, and garnered rave reviews for her performances in The Canterbury Tales and one-off drama Bella And The Boys.
Billie played Doctor Who's sidekick Rose Tyler in 2005 and 2006, winning the National Television Awards for Most Popular Actress two years running. Following Doctor Who, Billie played Belle in ITV2's racy drama Secret Diary of a Call Girl. Billie will reprise her role as Rose in series four for three episodes.
Billie married presenter and DJ Chris Evans in 2001 after a whirlwind romance. They divorced in 2007 and, later that same year, Billie tied the knot with actor Laurence Fox.
