The Aztecs believed they were living in the fifth world and that the previous four was destroyed by the sun gods

The Aztecs saw themselves as the ‘people of the Sun’ and their divine purpose was to supply the Sun with nourishment by offerings of blood and hearts because without that, they believed, the Sun would disappear and the entire universe as they knew it, would come to an end.

They believed they were living in the time of the fifth Sun and that there were four worlds, or ‘Suns’ before theirs.

The first world was destroyed when Jaguars ate all the people because in-fighting among the gods angered the Black Tezcatlipoca, the sun god, and he ordered the Jaguars to devour all.

The gods created new people but they became disrespectful and failed to show the necessary honor to the gods. They were all turned into monkeys and blown off the face of the earth by a mighty hurricane.

Once again new people were created and Tlaloc became the next sun. He became angered by the incessant prayers for rain from the people and sent a fire rain that burnt away the entire earth.

A new earth was created and Chalchiuhtlicue became the new sun goddess. When she was told she was only faking her kindness, she cried blood and everyone on earth drowned in the ensuing flood.

The Aztecs were then created and no wonder they were so devoted in their attentions to the sun!

(Source)