The Gospels of Matilda, Countess of Tuscany, is a manuscript written and illuminated in Northern Italy toward the end of the eleventh century. A credible fourteenth century document states that it was presented by the Countess to the Benedictine monastery of Polirone, near Mantua. In the manuscript's pictorial cycle, the Cleansing of the Temple and the scenes related to it are iconographically extra ordinary. An understanding of them must begin with a study of their ideological sources, closely related historic figures, Medieval writers who employed the figure of the Cleansing of the Temple, and the political-social movement of the Patarines. Then the Matilda Gospels' illuminations will stand revealed as the key artistic expression of the Gregorian Reform and as a prime document of some of the most important events and ideas of the Middle Ages. II. ART AND THE REFORM OF THE ELEVENTH CENTURY Church reform in the eleventh century was a heroic engage ment. Norman Cantor calls it one of the four great «world revolutions» of Western history.! The authority of the papacy, the independence of the church, and the very leadership of Medie val society were its mortally contested issues critical both to history and to political theory.2 Gregory VII and Matilda of Tuscany were but two of the vivid personalities among its partisans. But in the history of art the struggle has been nearly invisible.