Doctor Who star Jenna Coleman has confirmed she will leave Doctor Who after securing a role in ITV's new drama series Victoria, about the early years of the queen's reign.

The actress, who currently plays the part of the Doctor's companion Clara Oswald, will portray a young Queen Victoria after her ascension to the throne at the age of 18. The story will follow the ruler through her courtship and marriage to Prince Albert.

Coleman said: "I am delighted to be cast as Queen Victoria in this ambitious drama of her life. She is a vivid, strong, inspirational and utterly fascinating woman in British history and I can't wait to tell her story."

In a statement the BBC said: "It’s been officially confirmed that Jenna Coleman, who plays Clara Oswald, will leave Doctor Who during the new series which starts tomorrow, Saturday 19 September.

"However, it’s not been revealed exactly when Clara leaves and the question many are already asking is how will she part company with the Doctor?

"Jenna Coleman made her Doctor Who debut on 1 September, 2012 as Oswin Oswald in Asylum of the Daleks. She returned on Christmas Day of that year, playing Clara and remained with the Eleventh Doctor from the following episode, The Bells of Saint John, onwards. She stayed on board the TARDIS for all of Peter Capaldi’s episodes to date and after filming for the last series finished, Peter commented, ‘Jenna has been absolutely brilliant. I think she’s wonderful in the show, and she’s my favourite companion.’

"But Series 9 sees the Impossible Girl’s departure although the how, why and when are all questions we’ll have to watch the new adventures to find out…"

Victoria went on to rule for 63 years, and was the country's longest-serving monarch until she was overtaken by Elizabeth II on September 9 this year.

Further casting is under way for the eight-part drama, which will start filming in locations around the north of England this October.

As Coleman quits Doctor Who after three years, this is bad news for her character Clara - who reportedly will be killed off in November in an episode called Face the Raven.

Clara's death would be the first time an assistant has perished since 1982, when Peter Davison's Doctor lost his companion Adric (Matthew Waterhouse) in a spaceship crash.

According to reports, the show's boss Steven Moffat said Clara would be travelling with the Doctor (Peter Capaldi) and their friend Rigsy to a secret world. He added: "Not all of them escape alive. One of the three must face the Raven."

:: The ninth series of Doctor Who starts on Friday at 7.40pm on BBC One.