The Keystone of the Cathedral of Tortosa: The Coronation of the Virgin

This study examines the influence of the bishop’s and canons’ knowledge on the design of the presbytery’s keystones in Tortosa Cathedral, which has been governed by the Beati Augustini rule since 1155. The iconography representing the Coronation of the Virgin (1439) constitutes a recurring theme in medieval architecture and is closely linked to references found in manuscript illumination starting from the late 12th century. The presence of thirty-two works by Augustine of Hippo in the Cathedral’s Chapter Archives allows for a comparative methodology between the iconographic analysis of the Coronation of the Virgin and the study of the liturgical space through Terrestrial Laser Scanning (TLS). It is concluded that the metrology of the keystone is established based on the symbolic numbers 10 and 100 from the De Civitate Dei codices, and the number 150 from Augustine of Hippo’s De Supra Psalterium. Alongside this Augustinian foundation, both the iconography and the act of setting the keystone are enriched by the numerous codices related to the Summa Aurea by Jacobus de Voragine.