Adam James
From Tardis Wiki, the free Doctor Who reference
Adam James played Macmillan in DW: Planet of the Dead. His godfather was Jon Pertwee, who played the Third Doctor. James is also one of David Tennant's best friends. They met while playing half brothers in a production of King Lear in 1999.
In 2011, he co-starred in the West End production of Much Ado About Nothing, which David Tennant and Catherine Tate starred in and executive produced.
In 2012 they acted together again, in the BBC radio play Twelfth Night (in which Tennant played Malvolio, and James played Sir Toby Belch).