AP Photo

The bronze likeness of Muammar Qaddafi’s nemesis was lying on his back in a wooden crate shrouded in the darkness of a museum warehouse. His name was Septimius Severus. Like Qaddafi, he was from what is now Libya, and for 18 years bridging the second and third centuries A.D. he ruled the Roman Empire. His birthplace, Leptis Magna—a commercial city 80 miles east of what the Phoenicians once called Oea, or present-day Tripoli—became, in every meaningful way, a second Rome. More than 1,700 years after the emperor’s death, Libya’s Italian colonizers honored him by erecting a statue of the imposing, bearded leader with a torch aloft in his right hand. They installed the statue in Tripoli’s main square (now Martyrs’ Square) in 1933—where it remained for a half century, until...