Movies:
* The Importance of Being Earnest (2002) - as Algernon Moncrieff
* The Merchant of Venice (2004) - as Lorenzo
* The History Boys (2006) - as Irwin
* The Other Man (2008) - as David
* The King's Speech (2010) - as Lord Chamberlain
* The Best Exotic Marigold Hotel (2011) - as Norman Cousins
* The Best Exotic Marigold Hotel (2015) - as Norman Cousins
* The Mummy (2017) - as Lord Carnarvon
* The Guernsey Literary and Potato Peel Pie Society (2018) - as Sidney Stark
* The King's Daughter (2022) - as Lord Fabien
Television:
* The Bill (1993-1997) - as DC Steve Collins
* Holby City (1999-2000) - as Dr. Neil Hudson
* Waking the Dead (2000) - as Dr. David Sheppard
* Ultimate Force (2002-2006) - as Major Martin "Marty" Walker
* Midsomer Murders (2003-2017) - as various characters
* Foyle's War (2007) - as Major Arthur Price
* The Tudors (2007) - as Thomas Howard, 3rd Duke of Norfolk
* Spooks (2008) - as Colonel David Scott
* The Hour (2011-2012) - as Hector Madden
* The Last Kingdom (2015-2022) - as Æthelred
* Vanity Fair (2018) - as Sir Pitt Crawley
* The Crown (2022) - as Lord Mountbatten
* The English (2022) - as Thomas, the Governess's son
This is just a selection of his work. He has appeared in many other projects, including theatre productions and radio plays.
You can find a more comprehensive list of his work on his IMDb page: [https://www.imdb.com/name/nm0495137/](https://www.imdb.com/name/nm0495137/)