The fourth series of British science fiction television programme Doctor Who began on 25 December 2007 with the Christmas special "Voyage of the Damned". Following the special, a regular series of thirteen episodes aired, starting with "Partners in Crime" on 5 April 2008 and ending with "Journey's End". "Partners in Crime" marked the debut of Donna Noble, as played by Catherine Tate, as a full-time companion to the Tenth Doctor. A short Children in Need special was also produced. The series started production on 8 August 2007 and concluded on 29 March 2008. This was the final full series to star David Tennant as the Doctor, however he would remain in the role until 2010, following a year's worth of specials.