Alexander Neckam’s Sacerdos ad altare, which survives uniquely in Cambridge, Gonville and Caius College, ms. 385/605, was among the last works composed by the abbot of St Mary’s Abbey, Cirencester. Written in the early thirteenth century, it consists of texts on subjects ranging from sacerdotal vestments to scribal instruments, and includes chapters that recommend readings in the Bible, the liberal arts and medicine, as well as in civil and canon law. The texts are followed by glosses on selected lemmata that comment on points of grammar and lexicography, illustrated by classical and biblical quotations and enlivened with occasional observations on monastic life and practices. The work attests to the educational commitment of the Austin canons, an Order that was widely recognized for their contributions to scholarship on grammar, theological exegesis and law.