William Henry Gates III, born on October 28, 1955, in Seattle, Washington, stands as one of the most transformative figures of the digital age, a pioneering businessman and philanthropist whose name is synonymous with the microcomputer revolution. As the co-founder of Microsoft, the world’s largest personal-computer software company, Gates played a pivotal role in bringing computing power to the masses. His relentless ambition and business acumen not only made him the wealthiest person in the world for much of his career but also positioned him as a leading global force for charitable change, reshaping how the ultra-wealthy approach philanthropy.

Raised in an upper-middle-class family, Gates was a precocious and competitive student who was sent to the private Lakeside School, where he was first introduced to computers and formed a crucial friendship with Paul Allen. Together, the two spent countless hours honing their programming skills on a school terminal, an obsession that would define their futures. In 1973, Gates enrolled at Harvard University, where he tackled rigorous coursework like Math 55, but his focus was increasingly drawn to the burgeoning field of personal computing. In 1975, after reading about the Altair 8800 microcomputer, Gates and Allen saw their opportunity and dropped out of Harvard to co-found Microsoft, a decision that would alter the course of technology history. Their big break came in 1980 when they licensed an operating system, later known as MS-DOS, to IBM, a deal that established Microsoft as a dominant force in the industry. Following the company’s initial public offering in 1986, the subsequent surge in Microsoft’s stock price made the 31-year-old Gates the world’s youngest billionaire in 1987, a title that preceded his long reign as the planet’s richest man.

For 25 years, Gates served as Microsoft’s CEO, steering the company through the explosive growth of the software market and cementing its monopoly on personal computer operating systems. He stepped down as CEO in 2000, succeeded by Steve Ballmer, and transitioned to the role of chief software architect, a position he held until 2008. He eventually stepped down as chairman of the board in 2014 to become a technology adviser to current CEO Satya Nadella, a role he maintained until resigning from the board entirely in 2020. As his professional focus shifted, Gates increasingly dedicated his attention to the Bill & Melinda Gates Foundation, which he co-chaired with his then-wife, Melinda French Gates. As the world's largest private charitable organization, the foundation has concentrated on combating transmissible diseases like tuberculosis, malaria, and polio, as well as addressing issues in global health, education, and poverty alleviation. Following their divorce and French Gates’s resignation in 2024, the foundation was renamed the Gates Foundation, with Gates serving as its sole chair.

Beyond his philanthropic empire, Gates has been a prolific founder and investor, establishing companies such as BEN, Cascade Investment, TerraPower, Gates Ventures, and Breakthrough Energy, focusing on everything from nuclear energy to climate change solutions. In 2010, he and fellow billionaire Warren Buffett launched the Giving Pledge, a commitment by the world’s wealthiest individuals to donate the majority of their fortunes to charitable causes. His contributions have been widely recognized; in 1999, Time magazine named him one of the 100 most influential people of the 20th century, and in 2016, he and French Gates were jointly awarded the Presidential Medal of Freedom for their philanthropic work. The subject of several documentary films, Gates continues to be a prominent public intellectual and author, releasing the first of his planned three-part memoir, Source Code: My Beginnings, in 2025, which offers a candid look at the early life and formative experiences that shaped one of history’s most consequential technology leaders.