This thesis examines the relationship between Western eschatological traditions and Bishop Burchard of Worms' extended exegesis on the subject of ‘speculative theology’ within Decretum, Liber Vicesimus (c. 1012-1025). Its purpose is to explore the influence of eschatological theology upon the composition of canon law and its relationship with the administration of pastoral care in the early eleventh century. This will be achieved by investigating the authorities Burchard employed, and the unique ways in which he structured his interpretation of the subject. Chapter one reviews the scholarship on early medieval eschatological exegesis, canon law, and penance, alongside that on Burchard of Worms. Chapter two provides an overview of the history of early medieval western eschatological exegesis (c. 33-1050) and the general conditions that contemporary ecclesiastics would have experienced in relation to the study and construction of eschatological texts. Chapter three considers the historical context for the composition of the Decretum and the manuscript traditions of the Liber Vicesimus. Chapters four, five, and six, extensively analyse the structures and contents of the Liber Vicesimus: Burchard and his team of compilers are shown to have drawn extensively and developed their interpretation of eschatology from Gregory the Greats’ exegetical works, as well as identifying other unique influences. Consequently the thesis demonstrates how Gregory’s exegetical works played a central role in building the textual foundations which shaped the theological parameters governing the eschatological thoughts, beliefs, and writings, of many ecclesiastics during this period. The thesis concludes that Gregory’s work provided churchmen with an authoritative moral framework and rhetoric for the discussion of eschatological phenomena that could be utilised in a variety of ways. It also suggests new ways in which historians should interpret the written traditions that shaped the structure and content of orthodox eschatological texts in this period.