This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Five painted screenfold books, held today in libraries and museums scattered across Europe, are grouped together by scholars not because any surviving record says they belong together, but because their painting style, their format and the way they organize the 260 day ritual calendar resemble each other closely enough that art historians believe they must share a common workshop origin somewhere in central Mexico. No one has settled exactly where that workshop was, or which people, Nahua speakers, Mixtec painters, or some other group entirely, produced it, and Elizabeth Hill Boone's study is careful to treat that uncertainty as a live scholarly question rather than a solved one.
What is not in question is how the five books survived at all. Spanish colonial authorities destroyed indigenous painted books on a large scale, treating the pictorial calendars and their deity imagery as idolatrous, and the overwhelming majority of what existed before contact is lost entirely. The Codex Borgia Group survived specifically because all five volumes left Mexico for Europe within decades of the conquest, carried away as curiosities, gifts or plunder before local destruction could reach them. Their preservation is a story about distance and accident as much as about the value anyone at the time placed on their content.
Reading them today asks something different of a viewer than reading an alphabetic text. There is no sentence to translate, only a dense pictorial vocabulary of day signs, deities and directional associations that a period reader would have known how to navigate and that modern scholarship has spent a century learning to reconstruct, day sign by day sign, image by image.