A centuries-old manuscript telling the story of the Aztec civilisation in pictograms is going on display in Mexico for the first time in 186 years.
The document, known as the Codex Azcatitlan, has been held in France's Bibliotheque Nationale since 1898, and had already spent decades outside Mexico before that. It is thought to have been drawn in the 16th Century, a few years after the arrival of the Spanish conquistadors in what is now Mexico, and is widely considered one of the most valuable and insightful tellings of Aztec history.
Among the scenes it depicts are the arrival of Hernan Cortes and the defence of Tenochtitlan.
France has lent the codex to Mexico to mark 200 years of Franco-Mexican relations. It will be exhibited at the National Museum of Anthropology in Mexico City from Thursday.
In return, Mexico has agreed to lend another priceless document, the Codex Boturini, to France for display there. Its pictograms narrate the migration of the Aztecs, also known as the Mexica, from their ancestral homeland to the shores of Lake Texcoco, where they built Tenochtitlan.
The temporary exchange of the two codices was agreed by Mexican President Claudia Sheinbaum and her French counterpart, Emmanuel Macron, during a visit by the latter to Mexico last year.
The arrangement sits within a much longer campaign. Mexico has lobbied for years for the return of historical artefacts taken from the country in past centuries, and according to its ministry of foreign relations more than 2,000 objects were successfully repatriated last year.
For visitors to the National Museum of Anthropology, the practical result is straightforward: a document that has not been seen in Mexico for 186 years will be in a case in Mexico City.
It is worth being precise about the accounting, however. The Codex Azcatitlan arrives in Mexico. The Codex Boturini leaves it. At the close of business, the National Museum of Anthropology holds exactly as many codices as it held on Wednesday.
The same is true in Paris, where the Bibliotheque Nationale gives up one manuscript and receives one manuscript. Under any recognised standard of accounting, both institutions have stayed precisely the same size.
This is not a repatriation. It is a rotation. The Questionable Times notes approvingly that in codices, as in trade, the Franco-Mexican relationship is now perfectly balanced at 200 years.
The Department of Unnecessary Research recommends extending the principle to the rest of the caseload. Each of the 2,000-odd objects repatriated last year could be matched by an object dispatched in the other direction, holding the total quantity of history in each country constant while every individual claim is satisfied.
Both loans are described as temporary, and the Department looks forward to the return leg. Mexico would finish the process with exactly as many artefacts as it started with, which is the only outcome both governments could sign.