Howard of the Marines in Peter Weir's Master and Commander: The Far Side of the World alongside Paul Bettany and Russell Crowe, and appeared in Valkyrie with Tom Cruise playing Sgt.

Other film credits are Angels and Insects, Franco Zeffirelli's Jane Eyre and Tea with Mussolini, and Heroes and Villains directed by Selwyn Roberts.

Larkin also appeared in the 2007 episode of Doctor Who "The Shakespeare Code" and the 2012 low-budget horror film The Facility (originally titled Guinea Pigs) directed by Ian Clark.

[3] He appeared in three episodes of the fourth season of Black Sails, starring his brother, Toby Stephens.

In 2013 he starred in the television revival of Yes, Prime Minister as Bernard Woolley,[4] reprising the role he had played in the Gielgud Theatre in London's West End.