Devotion to the Virgin of Seven Sorrows flourished in the Low Countries in the late fifteenth century during a period of recovery from civil war, famine and economic instability. The Burgundian-Habsburg court took a special interest in this popular lay movement and, in an unusual move, sponsored a competition to generate a liturgy – a plainchant office and mass – for the growing devotion. This article identifies new sources for the text and music of the Seven Sorrows liturgy and ties them to the court’s competition. An examination of the surviving office and mass demonstrates the texts’ dependence on an earlier Marian celebration of the Compassion of the Virgin. The reworking of this older devotion reveals that the plainchant competition and the creation of the new Seven Sorrows liturgy were part of the court’s political agenda of restoring peace and unity to their territories.