Belgravia is a historical drama based on the 2016 novel by Julian Fellowes. A successful businessman and his wife give up their grandson (born out of wedlock ostensibly) to foster care rather than risk their reputation.

26 years later, the grandson is a successful businessman in his own right. He is introduced to his paternal grandparents, the aristocratic Brockenhurst's, and becomes heir to a title and a fortune.