"because they contained nothing but superstition and the devil's falsehoods, we burnt them all"
Bishop Diego de Landa burns Mayan books in 1562.
On the Yucatan peninsula on July 12, 1562 in the 4,000 year old town of Mani an auto-de-fa was held by Bishop Diego de Landa.
Fray Diego de Landa throws into the flames, one after the other, the books of the Mayas. The inquisitor curses Satan, and the fire crackles and devours. Around the incinerator, heretics howl with their heads down. Hung by the feet, flayed with whips, Indians are doused with boiling wax as the fire flares up and the books snap, as if complaining. Tonight, eight centuries of Mayan literature turn to ashes.
— Eduardo Hughes Galeano, Memoria del fuego (Memory of Fire Trilogy, 1986)
References:
Clendinnen, Inga. Ambivalent Conquests: Maya and Spaniard in Yucatan, 1517-1570, 2nd. ed. Cambridge: University Press, 1987
Landa: Relación de las cosas de Yucatán, ca. 1570 ed. Miguel Rivera, 1985. Madrid: Historia 16, p. 148.
Ostler, Nicholas. 2001. “Endangered Languages—lost Worlds.” Contemporary Review 279 (1631): 349–55.
Timmer, David E. 1997. “Providence and Perdition: Fray Diego de Landa Justifies His Inquisition against the Yucatecan Maya.” Church History 66 (3): 477–88.
This is perhaps the worst single act of superstition and falsehood in recorded history. We are only today beginning to understand what was lost, but that's with significant detective work, expert analysis lasting years, fighting poachers, and ultimately a great deal of inference and guesswork.
The Mayans were the premier scientists of the 16th Century, not just in the Western Hemisphere but all around the globe. Most of the books destroyed were invaluable and irreplaceable, as we know from the few that escaped destruction and reference those no longer available. With the recent improvements in LIDAR and drones, we're discovering that Mayan cities were probably an order of magnitude larger than we believed. The Mayan cities of El Pilar and Caracol may well have been the two largest cities in the world in 1562, each at least 45% larger than third-place Beijing.