Commentary on the Apocalypse (Commentaria In Apocalypsin) is a book written in the eighth century by the Spanish monk and theologian Beatus of Liébana. It is a commentary on the New Testament Apocalypse of John or Book of Revelation. It also refers to any manuscript copy of this work, especially any of the 26 illuminated copies that have survived. It is often referred to simply as the Beatus. The historical significance of the Commentary is made even more pronounced since it included a world map, which offers a rare insight into the geographical understanding of the post-Roman world. Well-known copies include the Morgan, the Saint-Sever, the Gerona, the Osma and the Madrid (Vitr 14-1) Beatus codices.