Billie Paul Piper is an English actress and former singer. She is known for her role as Rose Tyler in Doctor Who and as Hannah Baxter in Secret Diary of a Call Girl. She was the youngest ever solo artist to debut at number one, although she is only the second youngest solo artist to have a number one single, with "Because We Want To", which reached number one when she was 15 years old. Her most famous role is as Rose Tyler, companion to The Doctor, in the television series Doctor Who on BBC from 2005 to 2006, a role she reprised in 2008 and 2010 and is set to reprise in 2013. In 2007, Broadcast magazine listed Piper at no. 6 in its "Hot 100" list of influential on-screen performers, the top woman on the list. From 2007 until 2011, she starred as the high-flying escort Belle de Jour in the TV series Secret Diary of a Call Girl.