The Trivulzio Book of Hours is one of the most important, and certainly the most costly, gifts ever presented to a Dutch cultural institution. Given in 2001 by a donor who wished to remain anonymous, the manuscript represents the return of a spectacular item of cultural heritage that had been presumed destroyed. The manuscript formerly belonged to the collection of the princes of Trivulzio in Milan, but by the early 20th century its whereabouts were no longer known. The manuscript was made in about 1470 in Flanders, probably in Bruges and Ghent, by several masters, each of whom supplied miniatures to the rich program of illumination: Lievin van Lathem from Antwerp, Simon Marmion from Valenciennes, and an illuminator from Ghent known as the Master of Mary of Burgundy. The latter’s portrait of Mary of Burgundy is at page 96. As a final step in painting this miniature, the artist laid on extremely delicate gold highlights, probably using a brush with only two or three bristles. The radiance around the dove is so fine as to be almost ethereal. The borders in this manuscript enliven the religious scenes and delight the viewer. At the side margin, for example, the artist has depicted, with careful mimetic exactitude, a rare hoopoe bird. Even today this bird is said to portend rain, although in the image it seems to portend the Holy Spirit. In the lower-right margin, the miniaturist has depicted a harpy, a rapacious monster with the head of a woman, the claws of a lion, and the wings of a bird of prey. While this figure illustrates the theme of the power and danger of women, it also presents a word play: the harpy plays a harp. Further representing female power is the figure group at the lower left. This woman who plays the fiddle and rides her man may be Phyllis, who is said to have ridden the great teacher Aristotle like a horse.