Codex Borgia

The physical object is a screenfold: strips of tanned deerskin glued end to end, folded concertina-fashion into 39 leaves of about 27 centimetres square, and surfaced with a thin white gesso that takes paint the way plaster does. Every leaf but the two outermost is painted on both sides, giving 76 painted pages, and the whole opens to something over ten metres. Leather covers protected the ends. Nothing about it is European: the format, the materials and the pigments are those of pre-conquest central Mexico, and the book was made to be opened at the panel needed rather than turned page by page.

Its organising subject is the tonalpohualli, the 260-day divinatory count formed by running thirteen numbers against twenty day signs. That count governed naming, marriage, war, planting and sacrifice, and a book like this was a working instrument for the specialist who read it rather than a devotional text. The pages are laid out as almanacs: the count divided into fives, into twenties, into the nine Lords of the Night, each division attached to particular deities, offerings, birds, trees and directions, with the fortune of the period signalled by what is shown rather than by anything written.

There is no phonetic writing in it at all. The Borgia Group manuscripts encode meaning entirely in image and convention, which is why they can be read by scholars working across languages and why the linguistic identity of the painters is still argued over. Its origin is disputed on the same grounds: the Puebla-Tlaxcala region and western Oaxaca are the usual proposals, and the painting belongs to what is called the Mixteca-Puebla style, so calling the book flatly Aztec overstates what is known. The reading order generally runs right to left, which matters because the long sequence in the middle of the book breaks that rule.

Pages 29 to 46 are the reason the Codex Borgia is known outside specialist circles. They are painted at right angles to everything around them, so the book must be turned ninety degrees to read them, and instead of almanac grids they run as a continuous sequence of dense, dark scenes: a black figure descending, skeletal deities, fire drilling, decapitation, streams of blood and water, a series of temple enclosures entered and left.

No agreed reading exists. Eduard Seler, writing around 1900, took the sequence as an astronomical narrative, the journey of Venus through the underworld and its reappearance. Karl Anton Nowotny, in the 1960s, argued the opposite: not sky but ground, a record of ceremonies actually performed in real temple precincts, the codex functioning as a liturgical script. Later readings have proposed a cosmogony, the creation and ordering of the world; a New Fire sequence; and a priestly initiation or visionary ordeal undergone by the reader himself.

The disagreement is not for lack of study. It is that the sequence supplies images without a text to anchor them, and Mesoamerican religious imagery is layered by design: a scene can be an astronomical event, a rite and a myth at once, because the culture did not hold those apart as separate categories. Every proposed reading fits some panels well and others badly, and none has displaced the rest.

What can be said plainly is that the section is unique. Nothing else in the surviving corpus of Mexican religious manuscripts runs like it, and any account of pre-conquest cosmology that leans on these pages is leaning on material whose meaning is genuinely undetermined rather than merely obscure.

The Spanish destruction of Mesoamerican books was systematic rather than incidental. Missionaries treated the painted manuscripts as instruments of idolatry and burned them in quantity; Diego de Landa's burning of Maya books at Mani in 1562 is the best documented episode, but the practice was general across the conquered territories, and native lords destroyed or hid books themselves once possession became dangerous. The result is that of a manuscript tradition which must have run to many thousands of volumes, only a handful of pre-conquest books survive anywhere in the world, and they are counted one by one.

The Codex Borgia's own history before the eighteenth century is blank. It is named for Cardinal Stefano Borgia, in whose museum at Velletri it is first securely attested, and it passed with that collection to the Vatican after his death in 1804, reaching the Apostolic Library itself in 1902. Two accounts circulate of how it came to Europe: an oral tradition at the Congregation for the Propagation of the Faith that it was rescued in 1762 from a burning in Mexico, and a story reported by Alexander von Humboldt that it had belonged to the Giustiniani family in Rome, was damaged by fire in the hands of neglectful servants, and was retrieved by Borgia. Both are accounts given rather than established fact, and neither is independently documented.

Whichever is nearer the truth, the point stands. The survival of the single most important source for central Mexican religion was accidental, and by both accounts a near miss.