In your review of “Treasures of Heaven: Saints, Relics, and Devotion in Medieval Europe” at the British Museum in London you mention Venice in passing, but much of Venice’s history rests on the relics of St. Mark the Evangelist (“Holy Jewels,” June 25, 2011). Stolen from Alexandria by two crafty Venetian merchants in 828, these relics were the key to the Serenissima’s escape from the clutches of Byzantium. By 1204, the Fourth Crusade was led to Constantinople by dodge Enrico Dandolo in person. That was the beginning of the Byzantine empire’s sorry end in 1453, when its capital succumbed to the Turks. Such was the power of the flag of St. Mark with its winged lion. As you put it, “Christians in the Middle Ages believed that the relics of a saint could be used to intercede with God just as saints had done in life.” The pull of religious relics was enormous, indeed. Of course, it faded by Napoleon’s time, and in 1797 he gingerly extinguished Venice as an empire without any fear of St. Mark, let alone his bones. Ever since, relics became subject to mere shows, such as the one at the British Museum. The very idea would have been inconceivable a millennium ago or so.