Seaborne brigands were greatly feared in the ancient world. Pirates not only preyed on merchant ships and fishing craft in the Mediterranean but also wreaked havoc on coastal townstaking men, women, and children to ransom or sell as slaves; raiding treasures; and exacting tribute from fearful town leaders.

Responding to the threat of piracy, the Greeks established their primary cities inland for protection and even in their North African and Sicilian outposts they left coastal land uncultivated. Mariners feared pirate ships around every promontory and sought protection from the...