One of the church’s most celebrated treasures has also been the most poorly guarded: Not once but twice, a diminutive marble sculpture of the Virgin and Child by Michelangelo has disappeared—first carried off by French revolutionaries and then by the Nazis—and both times been recovered. The Italian Renaissance sculptor-painter probably created the piece for Siena Cathedral, but prosperous Bruges merchants are said to have brought it north, installing it in what is still to this day one of the city’s most beautiful sanctuaries.