This is the fourth in a series of catalogues that present descriptions and complete cycles of illustrations of all existing manuscripts of the "Commentary on the Apocalypse" written by the 8th-century Spanish monk Beatus. The entire corpus, which spans the 9th to the 13th century, constitutes the greatest single tradition of Apocalyptic writing in the Middle Ages. The manuscripts catalogued here are from the 11th and 12th centuries: the Silos Beatus in London; the Corsini Beatus in Rome; the Turin Beatus; the Osma Beatus; the Leon Fragment and the Berlin Beatus. All illustrations in these six manuscripts are reproduced and each catalogue entry discusses the location of production, the work of the outstanding illuminators and scribes, as well as details of codicology. A short introduction places the manuscripts in their historical context and analyzes the style of the miniatures. The volume includes a bibliography, relevant tables, and an index.