Bill Gates

William Henry Gates III co-founded the company that made the personal computer ordinary, was the richest person in the world for most of two decades, and has committed almost everything he made to a foundation that is meant to spend it and then close.

Seattle, 1955

He was born on 28 October 1955 in Seattle. His father, William H. Gates Sr., was a prominent lawyer. His mother, Mary Maxwell Gates, sat on the boards of banks and charities, including the national board of United Way. The family was comfortable, competitive and civic-minded; dinner-table discussions and family games were taken seriously.

At thirteen he went to Lakeside School, a private school in Seattle. In 1968 the school’s mothers’ club paid for a terminal linked to a time-sharing computer. Gates became obsessed with it. So did an older student, Paul Allen. The two used up the school’s computer time, found ways to get more, and as teenagers were paid to find bugs in a local company’s system and to write a payroll program. They also started a small business, Traf-O-Data, that analysed traffic counts.

Harvard and the Altair

He went to Harvard in 1973, meaning, his parents hoped, to become a lawyer. He spent much of his time in the computer lab and playing poker.

In December 1974 Allen showed him the cover of Popular Electronics, which featured the Altair 8800, a cheap computer kit. The two called its maker, MITS, in Albuquerque, and offered a version of the BASIC programming language for it. They did not have one. They wrote it in about eight weeks, using a simulator on Harvard’s computer, and Allen flew to Albuquerque to demonstrate it. It worked the first time.

On 4 April 1975 they founded Micro-Soft — later Microsoft — in Albuquerque. Gates left Harvard to run it. In 1976 he wrote an open letter to computer hobbyists complaining that most of them were copying Microsoft’s BASIC rather than paying for it. It set out an idea that was not obvious at the time: that software was a product people should pay for, separately from the machine.

The IBM Clause

In 1979 Microsoft moved to the Seattle area. In 1980 came the deal that made it.

IBM was building a personal computer and needed an operating system. Microsoft did not have one either. It bought one, called QDOS, from a small Seattle company for roughly $50,000, adapted it, and supplied it to IBM as PC-DOS. The crucial term was in the contract: Microsoft licensed the software to IBM rather than selling it, and kept the right to sell its own version, MS-DOS, to other manufacturers.

When other companies began making cheaper copies of the IBM PC, they all needed an operating system, and Microsoft sold it to all of them. IBM had built the hardware standard. Microsoft owned the software that ran on it. It is one of the most consequential contract terms in business history, and it is told at length in the site’s Microsoft business profile.

Windows

Microsoft released the first version of Windows in 1985. It was slow and not much used. Gates kept investing. Microsoft went public on 13 March 1986, and its shares made Gates a billionaire at thirty-one.

Windows 3.0 in 1990 was a success, and Windows 95, launched with an enormous marketing campaign, became a cultural event. Microsoft Office became the standard set of programs for offices around the world. In 1995 Gates wrote a memo, “The Internet Tidal Wave”, turning the company towards the web and its own browser, Internet Explorer.

He ran the company in a demanding, detail-obsessed style, famous for challenging employees in meetings. He married Melinda French, a Microsoft manager, in 1994. From 1995 he was ranked by Forbes as the richest person in the world in most years until 2017.

The Antitrust Case

Microsoft’s dominance brought the US government after it. In 1998 the Department of Justice and many states sued, arguing that Microsoft had illegally protected its Windows monopoly, notably by bundling Internet Explorer with Windows to crush the rival browser Netscape.

Gates’s videotaped testimony, in which he appeared evasive and argued over the meaning of ordinary words, damaged him badly. In 2000 a judge ordered that Microsoft be split in two. An appeals court overturned the break-up order in 2001, while agreeing that the company had broken the law, and the case was settled with restrictions on Microsoft’s conduct.

In January 2000 he handed the chief executive job to Steve Ballmer and became chief software architect.

The Foundation

In 2000 he and Melinda combined their earlier charities into what is now the Gates Foundation. It became the largest private charitable foundation in the world, focusing on vaccines, malaria, polio, maternal and child health, agriculture and, in the United States, education. In 2006 Warren Buffett pledged most of his fortune to it. In 2008 Gates stopped working full time at Microsoft to run the foundation, and in March 2020 he left Microsoft’s board.

In 2010 he and Buffett launched the Giving Pledge, asking the world’s richest people to promise to give away most of their wealth. He has also invested heavily in climate technology through Breakthrough Energy and in nuclear power through TerraPower.

In May 2025 he announced that he would give away almost all of his remaining fortune — about $200 billion, with the foundation’s own spending — and that the foundation would close in 2045, rather than decades after his death as first planned. For 2026 the foundation approved a record budget of about $9 billion.

Divorce and Scrutiny

Bill and Melinda French Gates announced their divorce in May 2021, after twenty-seven years of marriage. They have three children: Jennifer, Rory and Phoebe. Melinda French Gates left the foundation in 2024.

His meetings with the financier Jeffrey Epstein, between 2011 and 2014, after Epstein’s conviction, have drawn continuing criticism. In 2026 he apologised to foundation staff, and in June 2026 he told a US House committee investigating the Epstein case that meeting Epstein had been “a grave error in judgment”, and that he had never taken part in any wrongdoing.

In February 2025 he published Source Code, a memoir of his early years, in which he wrote that he would probably have been diagnosed with autism had he been a child today.

Paul Allen

The partnership that started Microsoft did not last. Paul Allen was diagnosed with Hodgkin’s lymphoma in 1982 and left the company’s day-to-day work in 1983, keeping his shares. In his 2011 memoir, Allen wrote that he had overheard Gates and Steve Ballmer discussing how to reduce his stake while he was ill; Gates later apologised and said he remembered the period differently. The two remained friends. Allen died in October 2018, and Gates wrote that Microsoft would never have happened without him.

Gates’s later writing turned towards the problems his foundation works on. In How to Avoid a Climate Disaster (2021) he argued that the world needs to reach net-zero emissions and that most of the technology needed to do so has not yet been invented, which is why he funds it.

He has kept a public reading list for many years, and his book reviews and annual letters have made him one of the most widely followed voices on global health.

The measure of him comes in two halves. In the first, he made software the most valuable part of computing and turned it into one of the greatest fortunes ever made. In the second, he set out to give that fortune away faster than almost anyone has given anything away — with a deadline.

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