This was a Man - Jeffrey Archer

In Whitehall, Giles Barrington discovers the truth about his wife Karin from the Cabinet Secretary. Is she a spy or a pawn in a larger game?
Harry Clifton sets out to write his magnus opus, while his wife Emma completes her ten years as Chairman of the Bristol Royal Infirmary, and receives an unexpected call from Margaret Thatcher offering her a job.

Sebastian Clifton becomes chairman of Farthings Kaufman Bank after Hakim Bishara resigns for personal reasons. Sebastian and his wife Samantha’s talented daughter, Jessica, is expelled from the Slade School of Fine Art, but her aunt Grace comes to her rescue.

Lady Virginia is about to flee the country to avoid her creditors when the Duchess of Hertford dies, and she sees another opportunity to clear her debts and finally trump the Cliftons and the Barringtons.

In a devastating twist, tragedy engulfs the Clifton family when one of them receives a shocking diagnosis that will throw all their lives into turmoil.