A precious Book of Hours, kept at the O¨sterreichische Nationalbibliothek in Vienna and so far neglected by the history of illumination studies, is a good example of the production of luxury codices anchored to the tradition of the late Gothic taste at the court of Alfonso the Magnanimous, king of Naples from 1442 to 1458, a taste that cohabited with other trends in fashion in the capital of the kingdom. A more careful analysis of the style of the illuminations of the codex allowed to hypothesize a direct commission of the sovereign and to attribute a good part of the execution of the scenes to Leonardo da Besozzo, painter and illuminator of Lombard origin active in Naples since the third decade of the fifteenth century. Passed to his son Ferrante after the death of the Magnanimous (1458), it is likely that the Book of Hours arrived at the Savoy's collections on the occasion of the wedding between Anna of Savoy and Prince Federico of Aragon celebrated on September 11, 1478. Federico of Aragon (1451-1504) was the third of Ferrante's six sons, while Anna of Savoy (1455-1480) was the daughter of Duke Amedeo IX and Iolanda of France, and therefore sister of Duke Charles I (1468-1490). Thanks to the support of his uncle Louis XI, king of France, Charles had been recognized as the new duke of Savoy at the death of his brother Filiberto I, which occurred in 1482, and at only 17 years, in 1485, he married Bianca of Monferrato. On that occasion, the very young duke ordered to illuminate the bipartite Savoia-Monferrato coat of arms on the title page of the codex that had already belonged to Alfonso the Magnanimous.