The Highest Paid Athlete in History - Gaius Appuleius Diocles

Diocles, a Lusitanian Spaniard who lived from 104 to 146 AD, earned 35,863,120 Roman sesterces in his lifetime - a figure that would amount to about $15 billion in today's money. The number is inscribed on a monument in Rome, erected for Diocles by his fans at the end of a 24-year career. The most famous races took place at Circus Maximus, a sports arena in Rome.

Races began when the emperor dropped his napkin and ended seven laps later. Those who didn't get maimed or killed and finished in the top three won prizes. Diocles most commonly raced four-horse chariots, and in most of his races he came from behind to win. Diocles is also notable for owning an extremely rare ducenarius, a horse that had won at least 200 races. Records show that he won 1,462 out of the 4,257 four-horse races he competed in.