Around the year 776, a monk by the name of Beato or Beatus, possibly the abbot of the monastery of Santo Toribio de Liébana, wrote a work entitled Comentarios al Apocalipsis (Commentary on the apocalypse), which had an extraordinary success in the following five centuries. Thanks to his great erudition, Beato combined in this text, as a summa, many commentaries on the topic of the apocalypse by such authors as Saint Irenaeus of Lyon, Saint Gregory the Great, Saint Isidore of Seville, and the 4th-century scholar Ticonius. The genre of apocalyptic literature appeared in the Jewish tradition in the second century BC and had never ceased to be practiced. Obsessed like his contemporaries with the imminent coming of the end of the world, which, according to the calculations of the six ages was to take place in the year 800 (838 in the Spanish era), Beato wrote this work for the edification of his monks. He emphasized that, after the final terrifying catastrophes announced by Saint John the Evangelist, good would triumph over evil. The original codex, which most likely was illuminated, has not been preserved. Even though the dreaded date passed without the world coming to an end, copies of Beato’s work continued to be made in the monasteries of the peninsular north (only one extant manuscript was written abroad). Then came the terrifying year 1000 and other feared dates, so the text, linked to a fixed cycle of illustrations, continued to appeal to readers. Thirty-five manuscript copies dating from the ninth century to the 13th century have survived. By semantic extension, these manuscripts are called beato, and 26 of them are illuminated. Two are preserved at the National Library of Spain. Presented here is one of the most beautiful copies, Codex Vitr/14/2, commissioned in 1047 by King Fernando I of León and Castille and Queen Sancha, and possibly done by Facundo in San Isidoro de León. Its 98 miniatures, endowed with amazing expressiveness, are distributed mostly on colorful horizontal stripes in a unique and unmistakable style that blends the Romanesque with various Mozarab and North African influences. Prominent among them are the Four Horsemen, the vision of celestial Jerusalem, the seven-headed snake, and the destruction of Babylon. The manuscript, owned by the Marquis of Mondéjar in the late 17th century, was confiscated with the rest of his library by Philip V during the War of the Spanish Succession.