The four bronze horses above the door of St Mark’s in Venice were carried off from Constantinople when the Fourth Crusade sacked the city in 1204. Napoleon took them to Paris in 1797 and set them on a triumphal arch; they came back to Venice in 1815 after his defeat. The originals now stand indoors, out of the weather, with copies on the façade.
Why this oneLoot twice over, and both times a statement about who was in charge.