This isn’t about who could be counted as a billionaire once their fortune has been converted into today’s money – so no, Roman general and politician Marcus Licinius Crassus (often called the 'richest man in Rome') isn't here.

It’s about who was the first to hit the magic ten figures. According to US newspapers of 29 September 1916, John D Rockefeller became the first billionaire when share prices of Standard Oil Company had shot up the previous day, although there are many – including Rockefeller’s own son – who think the newspapers had exaggerated.

Ron Chernow, in his biography of the wealthy industrialist, claimed the Rockefeller fortune peaked at around $900 million in 1913. (Don’t feel too sorry for him – that was worth nearly 2.5 per cent of the national economy.) If so, we need to look at another successful American entrepreneur: Henry Ford. The automobile and assembly line maestro crossed the billion mark in the 1920s. When asked by a reporter how it felt to be a billionaire, he famously muttered: “Oh sh*t!”

This article was first published in the September 2019 issue of BBC History Revealed