The Hours of Mary of Burgundy (German: Stundenbuch der Maria von Burgund) is a book of hours, a form of devotional book for lay-people, completed in Flanders around 1477, and now in the National Library of Austria. It was probably commissioned for Mary, the ruler of the Burgundian Netherlands and then the wealthiest woman in Europe. No records survive as to its commission. The book contains 187 folios, each measuring 225 by 150 millimetres (8.9 in × 5.9 in). It consists of the Roman Liturgy of the Hours, 24 calendar roundels, 20 full-page miniatures and 16 quarter-page format illustrations. Its production began c. 1470, and includes miniatures by several artists, of which the foremost was the unidentified but influential illuminator known as the Master of Mary of Burgundy, who provides the