Among the Biblioteca Vaticana's manuscript collection is a 9th- or 10th-century commentary on the Apocalypse of mysterious authorship, origin, and significance. In spite of the text's frequent association with two eighth-century figures—Charlemagne court scholar Alcuin of York and French abbot Ambrosius Autpertus—questions abound regarding its source. Knibbs proposes a close textual analysis to elucidate the author's beliefs with respect to the enigmatic book of the Apocalypse, as well as broader socio-literary issues of canonical authority and religious perspective.