Black Hours, Hispanic Society, New York

The black vellum and the presence of Maria's coat of arms, no longer blazoned with that of Aragon , support this theory.

[1] The book is an illuminated manuscript on black vellum, consisting of 152 folios, each measuring about 14.7 x 10.1 cm.

[1] The text is a version of the usual book of hours text, formally the Horae Beatae Marie Secundum usum curie romane (Hours of the Blessed Mary Following the Use of Rome).

The manuscript has space for a miniature on the page facing the start of each office.

The inclusion of St. Vincent Ferrer, who was canonized in 1455, gives us a terminus post quem.