Rich as Croesus is a phrase that has outlived its subject by more than two thousand years, yet the real king destroyed his own empire by misreading an oracle. This episode reconstructs the life of the last king of Lydia, born around 620 BC in what is now Turkey. He won the throne from his half-brother Pantaleon in a bitter succession fight, forced his own nephew out of Ephesus, and conquered the western coast of Asia Minor before deciding that treaties with the island Greeks would pay better than a naval war.

His lasting achievement was monetary. Lydian metalworkers used salt and heat to separate the gold and silver in electrum, which let Croesus issue the first standardized pure gold coin and make Sardis the financial center of the Mediterranean. He spent that gold on alliances and on Delphi. Then came the losses: a son killed by the very spear he had dreamed of, and a war against Cyrus the Great launched on the promise that he would destroy a great empire. The empire was his own.

• Before pure coinage, every electrum transaction meant weighing the metal and testing its purity with a touchstone, because one lump might be 70 percent gold and the next 40.
• Croesus sent Delphi a solid gold lion weighing 10 talents, roughly 600 pounds, earning Lydian envoys priority access to the oracle.
• In the tale told by Herodotus, the sage Solon refused to call Croesus the happiest of men, naming instead three ordinary Greeks who had died well.
• At the Battle of Thymbra, Cyrus put riders on his baggage camels at the front of his line, and the scent panicked the famous Lydian cavalry.
• Greek writers say rain saved Croesus from a burning pyre, while a single damaged cuneiform sign in a Babylonian chronicle leaves his real fate unknown.