Maya Codex of Mexico

The Maya Codex of Mexico is a fragmentary Postclassic Maya screenfold book, ten surviving pages painted on lime-coated bark paper, depicting deities associated with the planet Venus and a ritual calendar. It surfaced in the 1960s in the hands of a Mexican collector, Josue Saenz, having been dug up by looters rather than excavated, and was shown at the Grolier Club in New York in 1971, which gave it its former name, the Grolier Codex. That provenance and its unusual style led many specialists to condemn it as a forgery.

The Maya Codex of Mexico, formerly and still sometimes called the Grolier Codex after the New York club that first exhibited it in 1971, is reportedly said to have been found in a cave in Chiapas, Mexico, though, as with several looted or privately surfaced manuscripts recorded in this atlas, its exact recovery circumstances cannot be independently confirmed. The manuscript's original discovery narrative, presented when it was first shown to scholars in New York in 1971, included claims about a cave find in Chiapas that could not be independently verified at the time, contributing to decades of scholarly caution about the object that the later radiocarbon dating and 2016 technical study only partially resolved.

For four decades the codex sat under suspicion, reportedly recovered from a cave in Chiapas but without any controlled archaeological context. It is one of only four surviving Maya codices, the others being the Dresden, Madrid and Paris codices, all of which reached Europe in the colonial period. The Maya Codex of Mexico is now held by the Biblioteca Nacional de Antropologia e Historia in Mexico City under the National Institute of Anthropology and History, and on the strength of its radiocarbon date it is described as the oldest surviving manuscript of the Americas.

Long treated with suspicion by some Mayanist scholars, who questioned both its unclear origin and stylistic peculiarities compared to the three other securely accepted pre-Columbian Maya codices, the manuscript was radiocarbon-dated to a range of 1021 to 1154 CE, placing it in the Early to Middle Postclassic period, and later technical and iconographic analysis, notably work published around 2016 by Michael Coe and colleagues, argued strongly for its authenticity, a conclusion that has shifted, though not entirely settled, the scholarly consensus toward accepting it as a genuine pre-Columbian document. Its authentication has accordingly been treated by Mayanist scholarship as a gradual process of accumulating evidence rather than as a single decisive proof.

This is a status-arc case that moved from suspected forgery to ratified authenticity. The forgery case held that a modern faker could have assembled the book from the three long-accepted codices. The authenticity case accumulated against it: radiocarbon dating of the paper returned a range of 1021 to 1154 CE; the blue pigment was identified as genuine Maya blue, a recipe not reconstructed in the laboratory until the 1980s, after the codex had appeared; and it depicts deities and Venus-cycle details not documented in scholarship when it surfaced, which a forger could not have invented. A detailed 2016 reassessment by Michael Coe, Stephen Houston, Mary Miller and Karl Taube argued comprehensively for authenticity, and in 2018 Mexico's National Institute of Anthropology and History formally ratified it and renamed it the Maya Codex of Mexico.

The manuscript's content, a Venus-cycle almanac tracking the planet's synodic period for astrological and ritual timing purposes, is consistent with the kind of astronomical table found in the securely authenticated Dresden Codex, one of the arguments authenticity proponents have pointed to, since a forger working before Maya astronomical tables were well understood by outside scholars would have had to reproduce genuine Maya calendrical astronomy with a sophistication that seemed, to earlier skeptics, implausible for a modern fake. It is held today at the Biblioteca Nacional de Antropologia e Historia in Mexico City under the custody of the Instituto Nacional de Antropologia e Historia. This atlas records the 2016 authentication as the current best scholarly position while noting that, as with any object lacking a fully documented excavation history, some residual caution among specialists persists.