This 1984 photo shows a 29-year-old Bill Gates running his software empire from his wood-panelled home office, complete with a world map mural on the ceiling. That same year, he told a reporter about his plans to build a computer-powered home – a vision realised in the 1990s with Xanadu 2.0, his high-tech mansion in Medina, Washington.

By then, Gates’s influence on technology was unmistakable. After co-founding Microsoft in 1975 and helping to spark the personal computing revolution, he debuted on Forbes’ list of America’s richest in 1986 with a $315 million fortune (around $931m/£703m in today's money).

His wealth rocketed from there and, just one year later, he became one of the world's youngest billionaires. He officially left Microsoft in 2020, but continues to focus on philanthropic projects through the Gates Foundation.

Rare images reveal the secret home lives of the super-rich