Petrus Alamire was a noted music scribe, spy, and courier attached to the Brussels and Mechelen courts of Philip the Fair, Margaret of Austria, and Charles V. The workshop of Alamire and his immediate predecessors produced the largest and one of the most important groups of interrelated sources of northern Renaissance music, containing almost 700 works by some seventy composers, from Ockeghem to Pierre de la Rue. Many of the manuscripts contain elaborate decorations, the work of ateliers in Ghent and Bruges and of such superb illuminators as Simon Bening, Gerard Horenbout, the Master of the Prayerbook of 1500, and the Master of the David Scenes. The Treasury of Petrus Alamire presents the first comprehensive study of the fifty-one surviving manuscripts and ten fragments from his workshop. Eight essays discuss various aspects of the sources, such as the social and economic background, the illuminations, and the identification of the many scribal hands. An accompanying catalog gives detailed information about every source in the complex, including full-color illustrations for most.