1 The Aztec communion: tzoalli in religion and medicine of the Aztecs Jan G. Elferink and José Antonio Flores Farfán Introduction The Nahuas were one of the most important ethnic groups in Central Mexico when the Spaniards invaded the country in 1519. Among the Nahuas the Aztecs or Mexicas were the most dominant group, due to their military expansion. They had formed alliances with other Nahuas and had established the capital Tenochtitlan with a highly developed social stratification and religious culture. Together with their allies they had conquered a large part of central Mexico and had become very rich due to the institution of tributes which had to be delivered to them as conquerors. The Aztecs were only one of the many cultures that flourished in ancient Mexico. Yet, since they were the ruling group when the Spaniards arrived, we are pretty well informed regarding their historical language and culture. Especially the Spanish priests who accompanied or followed the army of Hernán Cortes wrote a wealth of information about the Aztecs and other Nahua groups. Among the so called codexes and other written sources the work of Bernardino de Sahagún outstands as one of the most important. Based on Aztec “informants”, whose voices were written down in Nahuatl, the language of the Aztecs, he composed what today is known as the Historia General de las Cosas de Nueva España and the Florentine Codex. The later work consists of paintings together with the Nahuatl text provided by his informants together with a Spanish translation. Another chronicler of outstanding quality was Diego Durán, who registered considerable information about Aztec religion. Likewise Sahagún, Durán provided several details with respect to the use of tzoalli by the Aztecs, the main focus of this paper. Religion was extremely important for the Aztecs and dominated all aspects of their life. They venerated a large number of gods which were attributed different valus and importance. Their most important god was Huitzilopochtli, the numen who had led them from their place of origin, Aztlan, to Central Mexico where they founded what would become the most famous capital of Mesoamerica, Mexico-Tenochtitlan. Other important gods were the sorcerer Tezcatlipoca, the god of wisdom and the arts Quetzalcoatl and the rain god Tlaloc, all ancient gods who had a place in many Mexican cultures, sometimes under different names, and which were often times appropriated by the Aztecs, such as the goddess of love, Tlazolteotl, who originally was a Tenec-Maya (Huastec) deity. Moreover, since the Aztec culture actually nurtured itself from other cultural traditions, such as those of the peoples they dominated, there were several other deities in the Mexica pantheon. An important aspect of Aztec religion and a very striking one for outsiders was the practice of a large numbers of human sacrifices. They were offered to the gods by cutting the chest open and taking the heart out so that it could be offered to the gods. The number of human sacrifices was so large that the Aztecs had to fight wars to get Comentado [JAFF1]: We should state why are we studying tzoalli, in the light of other studies that exits on the topic.. any hints?