Gary Carr will play a jazz singer called Jack Ross
Dame Kiri Te Kanawa is on board
Tom Cullen will play Lord Anthony Gillingham, a potential suitor for Lady Mary Crawley
Julian Ovenden has previously appeared in Foyle's War
Former EastEnder Nigel Harman will play Green, a visiting valet
Wife to Edward Fox and mother to Emilia Fox and Freddie Fox, Joanna David has also appeared in Foyle's War
Harriet Walter was given a damehood for in 2011for services to drama
