This English language volume on the collegiate church of Saint Peter in Leuven (Louvain), is the eighteenth in the series. In this monograph, the art historian M. Comblen-Sonkes has made an exhaustive study of three altarpieces. Two altarpieces are by Dirk BOUTS, the Holy Sacrament Triptych and the Saint Erasmus Triptych. The author proceeds to a rigorous stylistic and technical analysis with the help of laboratory documents such as X-radiographs and infrared reflectograms. Moreover exceptional archival sources, being the commissioning contract and the receipt of payment to the artist for the Holy Sacrament Triptych, fortunately shed light on the historical context and on the genesis of this type of paintings. The Edelheere Triptych, from which the central panel is a copy of the famous Descent of the Cross made by Rogier van der Weyden for the church of Our Lady outside the Walls in Leuven (now in the Prado), furnishes interesting elements to the issue of copying in the paintings of the fifteenth century Southern Netherlands.