At university, he appeared with the Cambridge Footlights notably as the evil Nalu in the 2009 pantomime "Ali Baba and the Forty Thieves"[2] and the Marlowe Society as Mercutio in a production of Romeo and Juliet.
[7] His theatre work includes appearing in the Trevor Nunn production of Rosencratz and Guildenstern are Dead by Tom Stoppard and The Resistible Rise of Arturo Ui by Bertolt Brecht at Chichester Festival.
[11] Northcote appears in the controversial Lars von Trier film Nymphomaniac[12] and as Mr. Vaughan in Belle.
[13] Northcote appears in the BBC drama SS-GB,[14] based on the book of the same name by Len Deighton and in series 2 to 5 of The Last Kingdom as the character Aldhelm, a Mercian lord and advisor to the monarchy.
He also appeared in The Imitation Game as mathematician Jack Good, with Benedict Cumberbatch as Alan Turing and Keira Knightley as Joan Clarke.