Est/Non Est: Crafting the Shield of Faith Trinity in Thirteenth-Century England

The Trinitarian diagram known as the Scutum fidei (Shield of Faith) presents a remarkable synthesis of one of the most complex doctrines of the Christian faith, utilising the three sides of a triangle to visualise the relationship between God the Father, God the Son, and God the Holy Spirit. Two of the earliest surviving examples of this diagram appear in English manuscripts made in the early thirteenth century, alongside works by pre-eminent scholars connected to the universities of Paris and Oxford: a copy of Peter of Poitiers’ Compendium historiae in genealogia Christi (BL Cotton MS Faustina B VII) and a compilation of Robert Grosseteste’s theological works (Durham Cathedral Library, MS A III 12). The presence of the Shield of Faith in these manuscripts suggests the diagram was developed in connection with the new university schools, but a full understanding of this relationship remains unexplored. This paper presents a reassessment of the intellectual and artistic milieu in which the Scutum fidei initially appeared, arguing that it was designed in conjunction with radical developments in Trinitarian doctrine adopted by the Fourth Lateran Council in 1215.