By the 12th dynasty, Amun became the major god worshiped in Egypt since his followers gained more political leverage in Egypt. He became the head of the triad of Thebes with his wife Mut and their son Khons. By the beginning of the 18th dynasty, Amun was associated with the earlier sun god, Ra, and known as Amun-Ra. Most of the myths about his origin and his creation are similar to those of Ra, but his shape was completely different. This new sun god was regarded as the uniter of the upper and the lower land of Egypt since it was the only national god to be worshiped here and there after worshiping several gods and goddesses. He was magnified also as the creator of the universe the defender of his eye. In addition to being the national god, Amun-Ra was the personal god who determines the length of mortal's lifespan and makes those who win his satisfaction live longer.
The main center for worshipping Amun was in the temple of Karnak that is regarded as one of the largest funerary buildings all over the world. The original building traces back to the 12th dynasty while many processes of restoration and enlargement have been made in the following reigns. The paintings on the Karnak walls highlight in detail the ceremonies of the annual festival of Opet that demonstrate how the sun god was taken every year from the Karnak at the time of the flood to visit the temple of Luxor and the rituals that had been performed for greeting the divine god and the offerings and sacrifices that had been made for the Triad.
For a short period of time Amun Ra's was replaced by Aton since Amenhutep IV, Ikhnaton, called for monotheism and forced the people to worship his new god who is embodied as the rays of the sun. Ikhnaton disbelieved in all the other gods and goddesses and the human personification for them and exerted a lot of effort to make the people believe in his own god and made Tal El-Amarna the capital of the country and the worship of Aton. The remains of his temples there explain the rituals performed for Aton. In the reign of Tutankhamun, the successor of Amenhutep IV, the worship of Amun was restored and the worship of Aton died out.
Many of the depiction of Amun associates him with the ram such as a ram-headed man, a ram with two curved horns, or a man with two straight parallel plums over his head. The reason for involving the ram in all the depictions of Amun, as Herodotus demonstrates, is the ancient Egyptian's belief in the myth of "The Hidden One". Amun was the god that no one can see and this was the secret of his power and the reason for calling him the Hidden One. One day Amun's son insisted on seeing the shape of his father, but Amun tricked him by covering himself with the skin of a ram and putting the head of the ram before his face in order to make him think that this is the real shape of his father. In addition to the depictions, the Egyptians were prohibiting sacrificing the rams except for the one that was sacrificed in order to use its skin as a cover for the statue of Amun before displaying it before the statue of Khons every year. Due to the great leverage of the national god Amun, a great wealth was accumulated for him and a large number of statues, slaves, and cattle were dedicated to him.
Amun was also associated with the wind and the air in other myths that tell about his major power that make the monsters of the dark water fear him and his great role as the guide of the mariners.