Augusta Ada King, Countess of Lovelace (née Byron; 10 December 1815 – 27 November 1852), also known as Ada Lovelace, was an English mathematician and writer best known for her work on Charles Babbage’s proposed mechanical general-purpose computer, the analytical engine. She was the first to recognize that the machine could be used for purposes beyond simple calculations. Lovelace is often called the first computer programmer.

Lovelace was the only legitimate child of poet Lord Byron and reformer Anne Isabella Milbanke. Lord Byron separated from his wife one month after Ada was born and died when she was eight years old. Though she was often sick as a child, Lovelace studied hard. She married William King in 1835. King became a Baron and was given the titles Viscount Ockham and 1st Earl of Lovelace in 1838. The name Lovelace was chosen because Ada was descended from the extinct Baron Lovelaces. This title made Ada the Countess of Lovelace.

Lovelace’s education and social activities introduced her to scientists such as Andrew Crosse, Charles Babbage, David Brewster, Charles Wheatstone, and Michael Faraday, as well as author Charles Dickens. These connections helped her learn more. Lovelace described her approach as "poetical science" and called herself an "Analyst (& Metaphysician)." At eighteen, her mathematical skills led to a long working relationship and friendship with Charles Babbage. She was especially interested in his work on the analytical engine. Lovelace first met Babbage on 5 June 1833, when she and her mother attended one of his Saturday night gatherings with their mutual friend, Mary Somerville, who was Lovelace’s private tutor.

Although Babbage’s Analytical Engine was never built and did not directly influence the invention of electronic computers, it is now known as a Turing-complete general-purpose computer, which predicted key features of modern electronic computers. Babbage is therefore called the "father of computers," and Lovelace is credited with several computing "firsts" for her work with him. Lovelace translated an article by military engineer Luigi Menabrea about the Analytical Engine, adding seven long explanatory notes. These notes described a method for using the machine to calculate Bernoulli numbers, often called the first published computer program. She saw the potential of computers to do more than just perform calculations, unlike many others, including Babbage, who focused only on that. Lovelace was the first to suggest that information such as music could be encoded and manipulated using such a machine. Her "poetical science" mindset led her to explore how people and society might use technology as a collaborative tool. Ada is widely honored, with her name appearing in programming languages, roads, buildings, institutes, programs, lectures, and courses. There are also plaques, statues, paintings, and literary and non-fiction works about her.

Biography

Lord Byron hoped his child would be a boy but was surprised when Lady Byron gave birth to a girl. The girl was named after Byron’s half-sister, Augusta Leigh, and was called “Ada” by Byron. On 16 January 1816, Lady Byron left for her parents’ home in Kirkby Mallory with their five-week-old daughter, as Lord Byron had ordered. At that time, English law allowed fathers to have full custody of children during separations, but Lord Byron did not try to claim his parental rights. He did ask his sister to keep him updated about Ada’s well-being.

On 21 April 1816, Lord Byron signed a legal agreement to separate from Lady Byron, though he did so reluctantly. He left England shortly after. Lady Byron continued to accuse her husband of immoral behavior for the rest of her life. These events made Ada famous in Victorian society. Ada never had a close relationship with her father, who died in April 1824 when she was eight years old. Her mother was the only major parent in her life. Ada did not see a family portrait of her father until her 20th birthday.

Ada did not have a close relationship with her mother. She was often cared for by her maternal grandmother, Judith, Hon. Lady Milbanke, who loved her very much. However, because of society’s rules, which favored fathers in separations, Lady Byron had to appear as a caring mother to others. She wrote anxious letters to Lady Milbanke about Ada’s health, with a note saying to keep the letters in case they were needed to prove her concern. In one letter, Lady Byron referred to her daughter as “it”: “I talk to it for your satisfaction, not my own, and shall be very glad when you have it under your own.” Lady Byron also had Ada watched by friends to check for any signs of bad behavior. Ada called these people the “Furies” and later said they exaggerated stories about her.

Ada often became sick, starting in childhood. At age eight, she had headaches that made it hard for her to see. In June 1829, she became paralyzed after a measles infection and was kept in bed for nearly a year. By 1831, she could walk with crutches. Despite her health problems, she studied math and science.

In early 1833, Ada had an affair with a tutor. She tried to run away with him after being caught, but the tutor’s family recognized her and told her mother. Lady Byron and her friends hid the incident to avoid a scandal. Ada never met her younger half-sister, Allegra, who was the daughter of Lord Byron and Claire Clairmont. Allegra died in 1822 at age five. Ada did meet Elizabeth Medora Leigh, the daughter of Byron’s half-sister, but Medora avoided Ada when they met at court.

Ada became close friends with her tutor, Mary Somerville, who introduced her to Charles Babbage in 1833. She respected and liked Somerville, and they stayed in contact for years. She also knew scientists like Andrew Crosse, Sir David Brewster, Charles Wheatstone, and Michael Faraday, as well as the writer Charles Dickens. At 17, Ada was introduced to court and became a popular young woman because of her intelligence. By 1834, she attended court events often and was described as dainty, though one friend, John Hobhouse, said she looked “large and coarse-skinned” but had some of Byron’s features. Ada disliked Hobhouse, likely because of her mother’s influence, but they later became friends.

On 8 July 1835, Ada married William, 8th Baron King, and became Lady King. Their homes included Ockham Park in Surrey, a Scottish estate near Loch Torridon, and a London house. Their honeymoon was at Ashley Combe in Somerset, a hunting lodge that William improved for their stay. From 1845, their main home was Horsley Towers, designed in a specific architectural style by Charles Barry, the architect of the Houses of Parliament. Ada later expanded the house.

They had three children: Byron (born 1836), Anne Isabella (called Annabella, born 1837), and Ralph Gordon (born 1839). After Annabella was born, Lady King had a long and painful illness that took months to recover from. Ada was a descendant of the extinct Barons Lovelace, and in 1838, her husband became Earl of Lovelace and Viscount Ockham, making Ada the Countess of Lovelace. From 1843 to 1844, Ada’s mother hired William Benjamin Carpenter to teach her children and act as a moral guide for Ada. Carpenter fell in love with her and encouraged her to express emotions, claiming he would never act improperly. When Carpenter tried to start an affair, Ada ended the relationship.

In 1841, Ada and Medora Leigh were told by Lady Byron that Ada’s father was also Medora’s father. Ada wrote to her mother: “I am not in the least surprised. In fact, you confirm what I have long suspected.” She blamed Augusta Leigh, not Byron, for the incestuous relationship. In the 1840s, Ada faced scandals, including rumors of affairs and gambling. She lost over £3,000 betting on horses and tried to create a mathematical model for successful bets in 1851, which failed. She owed money to a group of friends and had to tell her husband. She had a complicated relationship with John Crosse, the son of Andrew Crosse. After Ada’s death, John destroyed most of their letters as part of a legal agreement. She left him the only heirlooms her father had given her. During her final illness, she worried about John not being allowed to visit her.

From 17, when she was 17, Ada showed talent in math, which became a major part of her life. Her mother, who believed Byron had mental instability, had Ada study math and science early. Ada was taught by William Frend, William King, and Mary Somerville. In the 1840s, Augustus De Morgan helped her with advanced math topics, including the “Bernoulli numbers,” which she used in her famous algorithm for Babbage’s Analytical Engine. In a letter to Lady Byron, De Morgan praised Ada’s skill.

Work

Ada Lovelace was deeply interested in scientific ideas of her time, such as phrenology and mesmerism. After working with Charles Babbage, she continued to explore other projects. In 1844, she told a friend, Woronzow Greig, that she wanted to create a mathematical model to explain how the brain produces thoughts and feelings ("a calculus of the nervous system"). She never completed this work. Her interest in the brain was partly due to concerns she inherited from her mother about her possible mental instability. To learn more, she visited electrical engineer Andrew Crosse in 1844. That same year, she wrote a review of a paper by Baron Karl von Reichenbach, Researches on Magnetism, but it was never published. In 1851, she wrote to her mother about "certain productions" she was working on that connected math and music.

Lovelace first met Charles Babbage in June 1833 through their mutual friend Mary Somerville. Later that month, Babbage invited her to see a prototype of his difference engine. She became fascinated with the machine and visited Babbage often. Babbage admired her intelligence and called her "The Enchantress of Number." In 1843, he wrote to her:

In 1840, Babbage gave a lecture at the University of Turin about his Analytical Engine. Luigi Menabrea, an Italian engineer and future Prime Minister of Italy, translated Babbage's lecture into French. This was published in Bibliothèque universelle de Genève in 1842. Babbage's friend Charles Wheatstone asked Lovelace to translate Menabrea's paper into English.

From 1842 to 1843, Lovelace translated Menabrea's article and added seven notes, A to G, which were three times longer than the translation. The translation and notes were published in Taylor's Scientific Memoirs in September 1843 under her initials, AAL.

Explaining the Analytical Engine was challenging, as many scientists did not understand it, and the British government had little interest in it. Lovelace's notes even explained how the Analytical Engine differed from the Difference Engine. Her work was well received; scientist Michael Faraday supported her writing.

Lovelace and Babbage had a disagreement when the papers were published. Babbage tried to include an unsigned statement criticizing the government's treatment of his engine, which could have been mistaken as a joint declaration. When the publisher required the statement to be signed, Babbage asked Lovelace to withdraw the paper. She refused, as she had not known about the unsigned statement. Historian Benjamin Woolley suggested Babbage involved Lovelace for her reputation. Their friendship later recovered, and they continued to write to each other. In 1851, while dying of cancer, Lovelace asked Babbage to be her executor, though the letter did not grant him legal authority. A part of Worthy Manor's terrace, called Philosopher's Walk, was where Lovelace and Babbage were said to have walked, discussing math.

Lovelace's notes are important in the history of computers. Note G described a detailed method for calculating Bernoulli numbers using the Analytical Engine, which might have worked if the engine had been built. While Babbage's notes from 1837 to 1840 contain the first programs for the engine, the algorithm in Note G is often called the first published computer program. The engine was never completed, so the program was never tested.

In 1953, Lovelace's notes were republished as an appendix to Faster than Thought: A Symposium on Digital Computing Machines by B. V. Bowden. The engine is now seen as an early model of a computer, and her notes are recognized as a description of a computer and software.

Based on this work, Lovelace is often called the first computer programmer, and her method is called the first computer program.

Eugene Eric Kim and biographer Betty Alexandra Toole argued in Scientific American that it is incorrect to call Lovelace the first computer programmer. Babbage claimed credit for the algorithm in Note G in his autobiography. While Lovelace was not the first to write a program for the Analytical Engine—Babbage had written initial programs—most of them were never published. Historian Allan G. Bromley noted that Babbage prepared dozens of sample programs between 1837 and 1840, all earlier than Lovelace's notes. Dorothy K. Stein viewed Lovelace's notes as reflecting mathematical uncertainty, political goals, and social context rather than a scientific blueprint.

In a 1990 article, Allan G. Bromley wrote:

Bruce Collier stated that Lovelace helped promote the Analytical Engine but did not advance its design or theory.

Doron Swade noted that Lovelace published the first computer program but did not write it herself. He agreed she was the only person to see the engine's potential to handle more than just numbers.

In his book Idea Makers, Stephen Wolfram defended Lovelace's contributions. While acknowledging Babbage wrote earlier algorithms, Wolfram argued that Lovelace's computation of Bernoulli numbers was more advanced. He suggested her main achievement was explaining the machine's abstract operation clearly, which Babbage never did.

In her notes, Lovelace emphasized the Analytical Engine's ability to solve complex problems, unlike earlier machines. She saw its potential to do more than just calculations. She wrote:

This idea was a major step forward in understanding computing devices and predicted modern computing's implications a century early. Walter Isaacson linked Lovelace's insight to her observation of textile looms using punchcards to create patterns, similar to how Babbage's engine used punchcards. This insight is highlighted by historians like Betty Toole, Benjamin Woolley, and John Graham-Cumming, whose project Plan 28 aims to build the first complete Analytical Engine.

According to historian Doron Swade:

Note G also contains Lovelace's…

Commemoration

The computer language Ada was created by the United States Department of Defense. It was named after Ada Lovelace. The reference manual for Ada was approved on 10 December 1980. The Department of Defense Military Standard for Ada, MIL-STD-1815, was given the number that matched the year of Lovelace’s birth.

In 1981, the Association for Women in Computing started the Ada Lovelace Award. By 1998, the British Computer Society (BCS) began giving the Lovelace Medal. In 2008, BCSWomen started an annual competition for women students. BCSWomen also sponsors the Lovelace Colloquium, an annual conference for women undergraduates. In 2013, the University of Deusto in Spain created the Ada Byron Award for women in technology. This award later expanded to several Latin American countries.

Ada, the National College for Digital Skills, is a college in England that teaches digital skills. It has campuses in London (Pimlico) and Manchester (Ancoats). The college offers degree-level apprenticeships and serves students aged 16 to 19.

Ada Lovelace Day is an annual event held on the second Tuesday of October. It began in 2009. The goal is to increase the visibility of women in science, technology, engineering, and math. It also aims to create role models for girls and women in these fields. Events include Wikipedia edit-a-thons to improve the representation of women on Wikipedia.

The Ada Initiative was a non-profit group that worked to increase the participation of women in free culture and open source movements.

The Engineering Mathematics department at the University of Bristol is called the Ada Lovelace Building. The Engineering in Computer Science and Telecommunications College building at Zaragoza University is called the Ada Byron Building. A computer center in Porlock, near where Lovelace lived, is named after her. Ada Lovelace House is a building in Kirkby-in-Ashfield, Nottinghamshire, where Lovelace spent her early years.

In 2012, Google honored Lovelace with a Doodle and blog post on her birthday. In 2013, Ada Developers Academy was founded and named after her. Its mission is to help women and gender-diverse people gain skills and support to become professional software developers. In 2013, the BBC Radio 4 program Great Lives featured an episode about Lovelace, sponsored by TV presenter Konnie Huq.

As of November 2015, all new British passports include an image of Lovelace and Babbage. In 2017, Google honored Lovelace with a Doodle on International Women’s Day. In 2018, Satellogic launched a satellite named after Lovelace. In 2018, The New York Times published a delayed obituary for Lovelace.

In 2018, Senator Ron Wyden proposed a resolution in the U.S. Senate to designate 9 October 2018 as National Ada Lovelace Day. The resolution was passed unanimously. In 2020, Trinity College Dublin announced plans to create four new busts of women, including Lovelace. These busts were unveiled in 2023.

In 2022, a statue of Lovelace was placed at the former Ergon House site in London. The statue was created by Etienne and Mary Millner and based on a portrait by Margaret Sarah Carpenter. It was unveiled on International Women’s Day, 2022.

In 2022, Nvidia announced the Ada Lovelace graphics processing unit microarchitecture. In 2023, the Royal Mint released four commemorative £2 coins to honor Lovelace’s contributions to computer science.

In 2025, the National Portrait Gallery acquired three images of Lovelace, the only known photographs of her. Two were daguerreotypes by Antoine Claudet, taken around 1843. The third was taken by an unknown photographer and shows Henry Wyndham Phillips’ portrait of Lovelace.

In 2026, a statue of Lovelace was unveiled at the Hinckley campus of the North Warwickshire and South Leicestershire College.

The bicentenary of Lovelace’s birth was celebrated with several events, including:
– The Ada Lovelace Bicentenary Lectures on Computability, held by the Israel Institute for Advanced Studies from 20 December 2015 to 31 January 2016.
– The Ada Lovelace Symposium at the University of Oxford on 13–14 October 2015.
– Ada.Ada.Ada, a one-woman show about Lovelace, which premiered at the Edinburgh International Science Festival on 11 April 2015 and toured internationally.

Special exhibitions about Lovelace were held at the Science Museum in London and the Weston Library in Oxford.

In popular culture

Ada Lovelace is shown in Romulus Linney's 1977 play Childe Byron. In Tom Stoppard's 1993 play Arcadia, a young genius named Thomasina Coverly, who is inspired by Ada Lovelace (the play also includes Lord Byron), learns about chaos theory and suggests the second law of thermodynamics before these ideas are officially recognized.

In the 1990 steampunk novel The Difference Engine by William Gibson and Bruce Sterling, Lovelace gives a lecture about a program using "punched cards" that proves Gödel's incompleteness theorems decades before they are discovered. Lovelace and Mary Shelley are central characters in Jordan Stratford's steampunk series, The Wollstonecraft Detective Agency.

Lovelace appears in John Crowley's 2005 novel Lord Byron's Novel: The Evening Land as an unseen character. Her personality is shown through her notes and efforts to preserve her father's lost novel.

The 2015 play Ada and the Engine by Lauren Gunderson portrays Lovelace and Charles Babbage in a love story and imagines a meeting between Lovelace and her father after her death. Lovelace and Babbage are also main characters in Sydney Padua's webcomic and graphic novel The Thrilling Adventures of Lovelace and Babbage. The comic includes detailed footnotes about Ada Lovelace's history and uses actual letters as dialogue.

Poet Jessy Randall honored Lovelace in her 2025 poetry collection The Path of Most Resistance, which focuses on women scientists.

In the 1997 film Conceiving Ada, a computer scientist communicates with Lovelace in the past using "undying information waves."

Lovelace, known as Ada Augusta Byron, is played by Lily Lesser in the 2017 ITV series The Frankenstein Chronicles. She works as an "analyst" to help build a life-sized humanoid automaton. The machine's design is similar to Babbage's analytical engine. Her job is described as keeping her busy until she returns to studying advanced mathematics.

In the TV show Halt and Catch Fire, a character named Cameron Howe creates an operating system called "Lovelace."

The 2015 documentary Calculating Ada: The Countess of Computing by Dr. Hannah Fry explores Lovelace's life.

Lovelace and Babbage appear in the second season of the ITV series Victoria (2017), with Emerald Fennell playing Lovelace in the episode "The Green-Eyed Monster."

Lovelace is a character in Spyfall, Part 2, an episode of Doctor Who (series 12, 2020), played by Sylvie Briggs. The episode also features Charles Babbage and Noor Inayat Khan.

In the board game Ada's Dream (2025), players help Ada complete her work on the Analytical Engine. A clone of Ada Lovelace appears in the 2023 video game Starfield. Ada Lovelace is a playable leader in Sid Meier's Civilization VII.

Ada Lovelace Day is an annual event celebrating women in science and technology. A computer language developed by the U.S. Department of Defense is named "Ada." The British Computer Society (BCS) awards the Lovelace Medal. The BCS and the Alan Turing Institute sponsor the Lovelace Lectures. Durham University also hosts Lovelace Lectures. The Association for Women in Computing awards the Ada Lovelace Award. The Ada Initiative, which supports women in open technology, is named after her.

The Ada Lovelace Building is an engineering mathematics building at the University of Bristol and in Exeter Science Park. The Ada Byron Building is part of the University of Zaragoza's computer science department. The Ada Byron Research Centre is at the University of Malaga. The Ada Lovelace Institute is a think tank focused on data and AI. The Ada Lovelace Center for Digital Humanities is at FU Berlin. The ADA Lovelace Centre for Analytics, Data, and Applications is at Fraunhofer IIS. The Ada Lovelace Excellence Scholarship is offered by the University of Southampton. Adafruit Industries is a company named after her. The Ada Lovelace Centre is part of the Science and Technology Facilities Council in the UK. The Cardano cryptocurrency platform uses "Ada" as its currency and "Lovelace" as its smallest unit. An artwork at Microsoft's Building 99, called "Ada," uses artificial intelligence. In 2021, Nvidia's RTX 4000 GPU architecture was named "Ada Lovelace," the first to include both a first and last name. The Ada Byron University Programming Contest is held at the Polytechnic University of Valencia.

A green plaque is on Fordhook Avenue, near 5 Station Parade, Uxbridge Road, Ealing. Blue plaques are located at Mallory Park and St. James's Square. Ada Lovelace C of E High School in Greenford focuses on music, digital technologies, and languages. Ada Lovelace House in Nottinghamshire is used as council offices and may be rented to small businesses. The Ada Byron King Building is at Nottingham Trent University. The Ada Lovelace Suite is at Seaham Hall. The Lovelace Memorial is a Grade II Listed monument in Kirkby Mallory.

Publications

• Lovelace, Ada King. Ada, the Enchantress of Numbers: A Selection from the Letters of Lord Byron's Daughter and her Description of the First Computer. Mill Valley, CA: Strawberry Press, 1992. ISBN 978-0-912647-09-8.
• Menabrea, Luigi Federico; Lovelace, Ada (1843). "Sketch of the Analytical Engine invented by Charles Babbage… with notes by the translator. Translated by Ada Lovelace." In Scientific Memoirs, Vol. 3, edited by Richard Taylor. London: Richard and John E. Taylor. Pages 666–731. Archived on 29 May 2023. Also available on Wikisource: The Menebrea article, The notes by Ada Lovelace.

Six copies of the 1843 first edition of Sketch of the Analytical Engine with Ada Lovelace's "Notes" have been found. Three are kept at Harvard University, one at the University of Oklahoma, and one at the United States Air Force Academy. On 20 July 2018, the sixth copy was sold at an auction to an unknown buyer for £95,000. A digital copy of one of the Harvard University Library's editions is available online.

In December 2016, a letter written by Ada Lovelace was taken from Martin Shkreli by the New York State Department of Taxation and Finance because Shkreli owed money in taxes.