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 Masses, motets and secular works by some 70 composers, from Ockegham to Josquin to Willaert, the collection emphasizes the compositions of Pierre de la Rue, the court's main composer for decades. Many of the manuscripts were decorated with miniatures, borders, and eleborate painted initials, 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, detailed and fully illustrated study of the 51 surviving manuscriupts and ten fragments from his workshop. Eight essays by an international team of scholars discuss the social and economic background; the manuscripts as products of patronage; the illuminations; the musical repertory; Pierre de la Rue; Petrus Alamire; and the identification of the many scribal hands. The accompanying catalogue contains a physical description, dating, ownership and table of contents for every source, each with a substantial commentary, most with a full-colour illustration. An index of composers and compositions provides access to the sources and concordances of every work.