A large, headless, Roman-era bronze statue believed to represent Marcus Aurelius has reigned for 26 years as the resident philosopher-king of the Cleveland Museum of Art. With its lifelike presence, fluid drapery folds and dark, luscious patina, the sculpture is one of the museum’s signature treasures. Yet a mystery has always hovered over this exceedingly rare object. Where, exactly, did it come out of the ground, and who unearthed it?

Just as important, how many hands did it pass through before it found its way into the collection in 1986? The museum has long stated that the work might have been found in the 1960s in an obscure village in southwestern Turkey called Bubon, but it isn't sure.

The government of Turkey, on the other hand, is sure. It says that the bronze and nearly two dozen other works in Cleveland were looted from its soil, although the country has produced no evidence.

According to reports in the Los Angeles Times, Newsweek and Britain's Economist, the country has launched an international campaign aimed at repatriating such works. And it's proceeding in a way that could shake the foundations of encyclopedic museums with items collected before contemporary laws and international agreements intended to prevent looting and trafficking.