Figure of the month: 1520

Do you remember where you were and what you were doing on 30 June 2020? Let’s be honest: most of us will have to think about it and consult an old calendar to give an answer. Now imagine that we are not talking about you in 2020, but a gold bar, and the date we are interested in is 30 June 1520, more than 523 years ago. Mexican scientists have found a fascinating way to tackle this question, thanks to state-of-the-art technical and chemical analysis methods.

Witness of “La Nocha Triste” in Tenochtitlan, capital of the Aztecs

It was 30 June 1520 when the garrison of Spanish conquistadores stationed in Tenochtitlan made the disastrous decision to massacre all Aztec priests and nobles in a nearby temple. The enraged the population turned against the Spanish occupiers, and thanks to their manpower and the extent of their anger, the Aztecs succeeded in forcing the conquistadores out of Tenochtitlan. In retreating, the Spanish took everything of value with them, including the aforementioned gold ingot, which they lost during their flight.

State-of-the-art analysis methods and excellent knowledge of history

By chance, the 1.93 kg gold bar was found by construction workers in a park in Mexico City in 1981. Its provenance and site of its discovery remained a mystery for decades, until scientists from the Mexican National Institute of Anthropology and History (INAH) succeeded in unravelling the mystery of the gold ingot a few years ago. With a combination of special X-ray and chemical analysis, they were able to determine the age and origin of the gold ingot’s components and proved that it belonged to the treasure of the legendary Aztec ruler Montezuma. They were also able to clearly locate the gold ingot to Tenochtitlan at the time of La Nocha Triste. Finally, its location revealed the theft described above and the subsequent loss during the flight of the soldiers of fortune.