What is "new fire ceremony"

The New Fire ceremony (in Nahuatl xiuhmolpilli—the Binding of the Years) was an Aztec ceremony performed once every 52 years — a full cycle of the Aztec calendar— in order to stave off the end of the world.

The first Aztec New Fire ceremony described in ethnohistorical sources was in 1090, according to the Mapa Sigüenza. But there is evidence of New Fire ceremonies having been celebrated in civilizations other and earlier than the Aztecs, for example at Xochicalco in the 6th century. According to Bernardino de Sahagún, the last New Fire ceremony was held in 1507; the tradition started and ended with the Spanish conquest of Mexico in 1519–1521.

The fact that New Fire ceremonies had been celebrated before the rise of the Aztec empire suggests that the Aztecs had inherited the ceremony from earlier civilizations of central Mexico and that it was not an original Aztec invention. The Anales de Tlatelolco mention that the Aztecs upon achieving independence of the Tepanec state celebrated a New Fire ceremony that marked the beginning of the calendric count of the Aztecs. This suggests that the ceremony was also used as a dynastic foundation rite.