Lady Ada Lovelace, born in 1815, is considered by many to be the first computer programmer. Her mother, Annabella Milbanke, fostered an interest in logic problems and mathematics with Ada from a young age, supposedly to combat the influence of what she saw as the volatile and erratic temperament of Ada's father, the poet Lord Byron. Lord Byron is said to have been disappointed that Ada was not a son and left both her and her mother only months after Ada was born.
Ada's upbringing was very unusual for a young girl in the aristocracy in the 1800s. She had tutors in mathematics and science, including Mary Somerville, a Scottish astronomer who became the first woman admitted to the Royal Astronomical Society.
As an adult, Ada developed a friendship and working relationship with the mathematician and inventor Charles Babbage. In 1822, Babbage proposed a design for a Difference Engine, a mechanical calculator for tabulating polynomial functions. Such a machine, used by engineers, scientists, and navigators, would have been a significant economic advancement in the work of human data manipulation (so-called "human computers"), which required large amounts of time and introduced unavoidable human error into the computations.
Although in 1991, a perfectly functional version of Babbage's difference engine was built from his original plans, Babbage could never produce a working difference engine himself. While the British government's funding of Babbage was motivated by economics, Babbage himself was more driven by the possibility of pushing his invention to the next level. Before completing the difference engine, he became distracted by designs for an Analytical Engine, a machine meant to extend the applicability of the difference engine, and that would become the first general-purpose computer.
Ada, too, was fascinated by Babbage's plans for the Analytical Engine, and in 1843, she translated a description of the machine written by the Italian mathematician Luigi Menabrea. Babbage felt that Ada truly understood the complexity of the engine, far beyond other scientists at the time, and so asked her to include her own notes on its design and potential with her translation. Those notes, which became larger than the original work itself, were published in the Scientific Memoirs journal and included methods for using the machine to perform example computations. These methods, which would have worked had the machine ever been built, are considered the first computer programs.
Ada saw the potential applications for the Analytical Engine even beyond Babbage's initial proposal. Still, she dismissed the suggestion that it would in any way lead to the development of artificial intelligence. Her notes included the remark that the engine had "no power of anticipating any analytical relations or truths," an idea that remains a strong point of contention today.