Augusta Ada King, Countess of Lovelace (December 10, 1815 - November 27, 1852) is mainly known for having written a description of Charles Babbage's early mechanical general-purpose computer, the analytical engine.
Ada was the only legitimate child of the poet Lord Byron and his wife, Annabella Milbanke, a cousin of Lady Caroline Lamb, with whom he had an affair that scandalized Regency London. Ada was named after Byron's half-sister, Augusta Leigh, by whom he was rumoured to have fathered a child. It was Augusta who encouraged Byron to marry to avoid scandal, and he reluctantly chose Annabella. On January 16, 1816, Annabella left Byron, taking 1-month old Ada with her. On April 21, Byron signed the Deed of Separation and left England for good a few days later. He never saw either again.
Biographies differ as to whether Ada lived with her mother: one claims that her mother dominated her life, even after marriage; another claims she never knew either parent. One source tells that Anabella was fond of mathematics and taught Ada this art at an early stage of her life. She was privately schooled in mathematics and science; one of her tutors was Augustus De Morgan. An active member of London society, she was a member of the Bluestockings in her youth.
Her husband was William King, 8th Baron King, later 1st Earl of Lovelace. Her full name and title for most of her married life was The Right Honourable Augusta Ada, Countess of Lovelace. She is widely known in modern times simply as Ada Lovelace.
She knew Mary Somerville, noted researcher and scientific author of the 19th century, who introduced her in turn to Charles Babbage on June 5, 1833. Other acquaintances were Sir David Brewster, Charles Wheatstone, Charles Dickens and Michael Faraday.
During a nine-month period in 1842-1843, Ada translated for Babbage Italian mathematician Louis Menebrea's memoir on Babbage's newest proposed machine, the Analytical Engine. With the article, she appended a set of Notes which specified in complete detail a method for calculating Bernoulli numbers with the Engine, recognized by historians as the world's first computer program. She speculated that such a machine could create graphics or compose music; Babbage never built a working model.
However, biographers have noted that Lovelace struggled with mathematics, and there is some debate as to whether Lovelace understood deeply the concepts behind programming Babbage's engine, or was more of a figurehead used by Babbage for public relations purposes. As an early woman in computing, Lovelace occupies a politically sensitive space in the canon of historical figures in computer science, and therefore the extent of her contribution versus Babbage's remains difficult to assess based on current sources.
Ada Lovelace died at 37 of cancer, leaving 3 children. At her request, she was buried next to the father she never knew at the Church of St. Mary Magdalene in Hucknall, Nottingham.
On December 10, 1980, the U.S. Defense Department approved the reference manual for their new computer programming language, called "Ada".
Her image can be seen on the Microsoft product authenticity hologram stickers.
She is one of the main characters in the alternate history novel The Difference Engine by Bruce Sterling and William Gibson, which posits a world in which Babbage's machines were mass produced and the computer age started a century early.