Who’s who?

James Trenchard (Philip Glenister) The son of a market trader who’s worked his way up as a self-made man.

Philip told Radio Times: “He’s a cross between Donald Trump and Del Boy.

“He’ll go to the opening of an envelope and he sometimes makes a total fool of himself.”

Anne Trenchard (Tamsin Greig) James’s sensible wife has a lot of internal grief and angst. She’s the daughter of a schoolmaster, more educated than most women and a central character in an ongoing struggle with Lady Brockenhurst.

Thanks to her corset, Tamsin had to start seeing an osteopath soon after the filming had begun.

She says: “To be in a corset for 12 hours a day is a shock.”

Oliver Trenchard (Richard Goulding) The Trenchards’ son is caught in an unhappy marriage to ambitious wife Susan who has been unable to bear them a child – and gets the blame. Richard says: “Belgravia is about people falling in love with the wrong person and wanting to have sex with someone they can’t.”

Susan Trenchard (Alice Eve) A complex character who is struggling with her own frustrations – namely her marriage and her status – and takes matters into her own hands.

Alice explains: “Her husband keeps calling her barren but she has a hunch that she’s fertile. Then along comes this chap who is very front-footed in his pursuit.”

Lady Brockenhurst (Harriet Walker) Another strong matriarch who makes a wonderful sparring partner for Anne. She is hiding a deep grief, but is a calculating woman who always get her way. Despises the nouveau-riche. Dame Harriet, who starred in Downton, says: “People will probably compare Belgravia with Downton Abbey, but this is very different. “Where it is similar is the fact that Julian creates characters on every level of the social order.”

Charles Pope (Jack Bardoe)

A likeable, ambitious young man who’s an entrepreneur with a parentage that’s a highly-charged secret – which he’ll no doubt be the last to find out about.

He falls in love with Lady Maria Grey, who seems beyond his reach. Charles was plucked from drama school for Belgravia’s Jack, which is his first TV role.

Lady Maria Grey (Ella Purnell) An intelligent woman who is forced into marriage with the unsavoury John Bellasis, the next Earl of Brockenhurst.

She wants to travel and use her own head for business. And Charles Pope offers to give her just that.