Which man was Ada Lovelace's husband?

Ada Lovelace’s husband was William King-Noel, later the 1st Earl of Lovelace. The couple married on 8 July 1835, when Ada was 19 and William was known as Lord King, the 8th Baron King.

William and Ada had three children: Byron, Anne Isabella, and Ralph. In 1838, William was made Viscount Ockham and Earl of Lovelace, giving Ada the title Countess of Lovelace—the name by which she is now best known. “Ada Lovelace” was therefore a title-based name rather than her birth name.

William is sometimes called simply William King or Lord William King. He adopted the surname King-Noel after inheriting the Noel family estates and connections; these forms describe the same husband. He was not Charles Babbage, Ada’s celebrated collaborator, nor Augustus De Morgan, one of her mathematics tutors.

Ada’s marriage and aristocratic position gave her access to influential intellectual circles, but her mathematical reputation rests on her notes about Babbage’s proposed Analytical Engine, written several years after her wedding.