Complex sentence: The Spanish brought the European tradition to Mexico, although there were similar traditions in Mesoamerica, such as the Aztecs' honoring the birthday of the god Huitzilopochtli in mid December.
Split into simpler sentences: The Spanish brought the European tradition to Mexico, although there were similar traditions in Mesoamerica. The Aztecs had a similar tradition to honor the birthday of the god Huitzilopochtli in mid December.