Doctor Who
Thirteen actors have headlined the series as the Doctor. The transition from one actor to another is written into the plot of the show with the concept of regeneration into a new incarnation, a plot device in which a Time Lord "transforms" into a new body when the current one is too badly harmed to heal normally. Each actor's portrayal is unique, but all represent stages in the life of the same character. Together, they form a single lifetime with a single narrative. The time-travelling feature of the plot means that different incarnations of the Doctor occasionally meet. The Doctor is currently portrayed by Jodie Whittaker, who took on the role after Peter Capaldi's exit in the 2017 Christmas special "Twice Upon a Time".
Doctor Who (series 1)
David Tennant had been offered the role of the Doctor when he was watching a pre-transmission copy of "Casanova" with Davies and Gardner. Tennant initially believed the offer was a joke, but after he realised they were serious, he accepted the role and first appeared in the series finale "The Parting of the Ways". Tennant was announced as Eccleston's replacement on 16 April 2005. Other recurring characters for the series included Camille Coduri as Rose's mother Jackie Tyler, and Noel Clarke as Rose's boyfriend Mickey Smith. Other actors and television presenters who appeared in the series included Mark Benton, Zoë Wanamaker, Simon Callow, Eve Myles, Penelope Wilton, Annette Badland, Matt Baker, Andrew Marr, Corey Johnson, Simon Pegg, Anna Maxwell-Martin, Tamsin Greig, Shaun Dingwall, Florence Hoath, Richard Wilson, Jo Joyner, Davina McCall, Paterson Joseph, Anne Robinson, Trinny Woodall, and Susannah Constantine.