FBI returns 1527 letter from conquistador three decades after it was stolen from Mexican archives

The FBI returned a 1527 letter signed by Spanish conquistador Hernán Cortés to the Mexican government roughly three decades after it went missing from the country's national archives. 

The letter, which is a payment order for a pharmacy, was in Mexico's National Archives with 15 other historical documents signed by Cortés that were taken from the institution in the late 1980s or early 1990s, according to Supervisory Special Agent Kristin Koch.

The letter was signed about eight years after Cortés' expedition from Spain to Mexico that eventually led to the Aztec Empire's downfall.

The FBI returned the letter earlier this month after it was rediscovered at a Massachusetts-based auction house last year. A representative of the national archives of Mexico reached out to the FBI after seeing the letter on the auction house's website. 

It is unclear when or how the document was stolen, and how it came to the United States. "But we do know that it ended up in an auction house in California in the early '90s, and it moved through several different hands until it reached the person that consigned it to the auction house in Massachusetts," Koch said.

The other 14 documents with Cortés' signature are still missing.

"This manuscript, which is nearly five centuries old, preserves an important part of Mexico’s history and reflects the FBI’s ongoing commitment to protect cultural heritage, not only in the United States but around the world," Acting FBI Special Agent Christopher DiMenna of Boston said.

Follow Madeleine Hubbard on Twitter or Instagram.