People

Ada Lovelace

Ada Lovelace wrote what's often called the first computer program in 1843, a century before anyone built a machine that could run it. Her father was Lord Byron.

Published 02 October 2026

Quick Facts

Born: 10 December 1815, London
Died: 27 November 1852, aged 36, Marylebone, London
Full title: Augusta Ada King, Countess of Lovelace
Famous for: Notes on Charles Babbage's Analytical Engine, including an algorithm to compute Bernoulli numbers
Parents: Lord Byron and Anne Isabella Milbanke
Mentor and collaborator: Charles Babbage
Tutor: Mathematician Augustus De Morgan, among others
Lasting tribute: Ada Lovelace Day, held each October; the programming language Ada

The poet's daughter who was raised on sums

Ada was born Augusta Ada Byron, the only legitimate child of the poet Lord Byron. Her parents separated within weeks of her birth, and Byron left England in 1816. He never saw his daughter again and died in Greece when she was eight. Her mother, Annabella, was determined that Ada would not turn out like her wildly romantic father. The cure, she decided, was mathematics, logic and discipline. Ada was given rigorous tutoring in a time when girls from wealthy families were rarely taught such things. It did not entirely work. Ada kept a powerful imagination and later described her approach as 'poetical science'. She never stopped treating numbers as something creative.

A flying machine made of paper

As a teenager Ada became fascinated with flight. Around 1828 she worked on designs for wings, studying the anatomy of birds and thinking about materials and the weight needed to get a person airborne. She even considered steam power as a driving force. It was an early sign of her habit of turning big ideas into step-by-step problems. She also suffered serious illness as a girl, including a bout that left her bedridden for a long period, and she kept up her studies throughout.

The evening she met the Engine

In 1833, aged 17, Ada was introduced to Charles Babbage, the mathematician and inventor. He showed her a part of his Difference Engine, a mechanical calculator, and she was captivated by it. The two struck up a long friendship and correspondence. Babbage was already dreaming up something far grander: the Analytical Engine, a machine that could be given instructions on punched cards, much as Jacquard looms used cards to weave patterns. It was designed to store numbers and carry out a chain of operations, which is the basic shape of a modern computer. In 1835 Ada married William King, who became Earl of Lovelace in 1838, making her the Countess of Lovelace. She had three children, and she kept studying maths with tutors including Augustus De Morgan.

Note G, and why it matters

In 1842 an Italian engineer, Luigi Menabrea, published a description of the Analytical Engine in French. Ada translated it into English, then added her own notes, which ended up roughly three times longer than the original text. They were published in 1843 under her initials, A.A.L. The last of these, Note G, set out a detailed method for the machine to calculate Bernoulli numbers. That table of operations is widely regarded as the first published computer program, though the machine itself was never completed. She also made a leap that went beyond arithmetic. Ada saw that the Engine might handle anything that could be expressed in symbols, noting that it could in principle compose music of any complexity. She was also clear that the machine had no power to originate anything on its own; it could only do what it was told. That idea is still debated in discussions of artificial intelligence. Historians still argue over how much of the mathematics was hers and how much was Babbage's. What is clear is that her notes explained and imagined the machine's potential better than anyone else of the time.

Gambling, illness and an early death

Ada's later life was messier than her legend. She was drawn to ambitious schemes, including an attempt to devise a mathematical system for betting on horses, which left her in debt. She was ill for years and died of cancer at 36, the same age at which her father had died. At her request, she was buried next to Byron in the family vault at the church of St Mary Magdalene in Hucknall, Nottinghamshire. The father who never knew her finally had his daughter beside him.

Where her mark shows up now

Her work was largely forgotten until the 1950s, when Babbage's engines and her notes were rediscovered by computing pioneers. In 1980 the US Department of Defense named a programming language Ada in her honour. Ada Lovelace Day, held each October, celebrates women in science, technology, engineering and maths. You can see Babbage's engineering legacy at the Science Museum in London, which built a working Difference Engine No. 2 from his plans, and visit Byron's resting place at Hucknall, where Ada lies too.