In a world of raging financial markets and soaring wealth inequality, where it sometimes feels like billionaires are becoming a dime a dozen, Bill Gates stands out.

The Microsoft co-founder is not just another excessively rich tech mogul: he is the archetype of the computer nerd-turned-master of the universe, the forerunner of the generation of tech founders who now dominate the business world.

Nor is he just another megadonor with a saviour complex. The foundation he set up with his former wife, Melinda French Gates, has reshaped the philanthropic landscape, matching some big governments in its spending on global health and development. Nearly 250 of the world’s super-rich have signed the Giving Pledge that he championed along with Warren Buffett, promising to give most of their wealth to charity.