Downton Abbey Wiki

Diana Clark is the former mistress of Lord Sinderby and the mother of his illegitimate son, Daniel.



Diana Clark brings her son to Brancaster Castle in Northumberland on the presumption that she was invited there by Lord Sinderby and that he would be alone (when in truth she was not, but tricked into coming as part of a scheme by Thomas Barrow to get back at Lord Sinderby for insulting him in public).

Lord Sinderby's daughter-in-law Rose sees him panicking and asks him what her name is so she can "save" him. Rose immediately presents Diana as an old friend of hers, and gets Mary and Lord Grantham to play into it when they figure out who her son is. Both Rose's husband Atticus and Lady Sinderby remain unaware who Diana and her son really are.

Diana later leaves, thanking Rose for saving both Lord Sinderby and her from humiliation. She also asks her not to think badly of Lord Sinderby. Rose's quick thinking earns her Lord Sinderby's respect. She also uses the situation to make Lord Sinderby's butler, Stowell, (from whom Barrow learned the secret of Lord Sinderby's love child), treat her cousin Tom Branson with more respect (as Stowell had been rude to him earlier).


  • It is unknown if Diana and her son are Jewish like Lord Sinderby.
  • When Rose spoke to Stowell, she referred to Diana as "Mrs Clark" implying Diana is married.


Appearances and Mentions
Series 5 Episode 1 Episode 2 Episode 3 Episode 4 Episode 5 Episode 6 Episode 7 Episode 8 Christmas Special