The caissons were mobile frequently used from the Middle Ages onwards, as they were easy to handle and transportable. Traditionally they contained the trousseau of the brides. This chest, which retains only the front part of the original, shows three dukes Sforza, Galeazzo Maria, Gian Galeazzo and Ludovico il Moro on horseback and accompanied by squires. It was perhaps made for the marriage between Chiara, daughter of Galeazzo Maria Sforza, and Fregosino Fregoso, son of the Doge of Genoa Paolo, which took place in 1488.