Amun was a major Ancient Egyptian deity. In the 11th dynasty (c. 21st century BC), he rose to the position of patron deity of the Thebes. After the rebellion of Thebes, Amun acquired national importance, expressed in his fusion with the Sun god, Ra, as Amun-Ra. Ra is the ancient Egyptian sun god. By the Fifth Dynasty in the 25th and 24th centuries BC, he had become a major god in ancient Egyptian religion, identified primarily with the noon sun. It is hard to distinguish exactly when this combination happened, but references to Amun-Ra appeared in pyramid texts as early as the fifth dynasty. The most common belief is that Amun-Ra was invented as a new state deity by the Theban rulers of the New Kingdom to unite worshipers of Amun with the older cult of Ra around the 18th dynasty.