On television, he is best known for playing Bertie Pelham, the Marquess of Hexham, suitor of Lady Edith Crawley on Downton Abbey; their characters were married in the 2015 Christmas special that concluded the series. He has also starred in Midsomer Murders, The Amazing Mrs. Pritchard, Hotel Babylon, Silk, Waking the Dead, Drifters, Walter, Wallander, and Grantchester.