His parents, Nigel Davenport and Maria Aitken, are both successful British actors.
After graduating from university, he wrote to John Cleese, who co-starred with Davenport's mother in A Fish Called Wanda (1988). Although he had been hoping to get behind-the-scenes work in Cleese's film Fierce Creatures (1997), he wound up with a small part in the movie.
Landed his breakthrough role as Miles Stewart in the British cult hit This Life after a lengthy process, which required him to audition for the role multiple times.