This leaf is distinguished by a large initial P depicting Samuel, the last and one of the greatest of Israel’s judges. It introduces the text Preparte corda vestra domino et servite (“Prepare your hearts for the Lord and serve”). In the lower margin are the arms of the Visconti family, rulers of Milan, featuring an eagle (left) and a coiled serpent (right). At bottom center is the emblem of the Olivetan Order, a reformed branch of the Benedictines founded in 1319 known as the “white monks.” The Olivetan monastery in Milan was founded in 1400 and it appears that this leaf belonged to a set of choral books presented to the monastery by one of the Visconti, perhaps about 1439–47. The so-called Olivetan Master takes his name from a luxuriously illustrated psalter made for the order’s monastery in Milan, where he was undoubtedly a monk.