Liber Extra
His family (and hence its surname) probably originated in the Kentish village of Chillenden, though his parents are unknown. After becoming a monk at Christ Church Priory, he studied for a bachelorship in canon law at Canterbury College, Oxford from 1365 to 1378, before going to Rome to study the same subject at the papal curia. There he became Doctor of Canon Law, in 1383 or earlier, put together an index to the fourth book of the Decretals of Gregory IX (Repertorium quarti libri decretalium), wrote a commentary to the Regulae juris (Longleat, MS 35, fols. 187–206), and lectured on the fourth book of the Clementines (‘Reportata on the Clementines’). In 1383 the University of Oxford was involved in a dispute with St Frideswide's Priory, and Chillenden served as the former's proctor.