Amun had his origins in the Old Kingdom of Egypt, which describes a period of around 500 years in the middle of the third millennium BC. The Egyptian Empire reached its zenith in the New Kingdom, between around 1700 and 1000 BC; it was at this time that Amun came to be fused with Ra, and together they were known as Amun–Ra or Amun–Re.
According to Wikipedia, "Amun–Ra retained chief importance in the Egyptian pantheon throughout the New Kingdom ... in this period [he] held the position of transcendental, self–created creator deity par excellence; he was the champion of the poor or troubled and central to personal piety. His position as King of Gods developed to the point of virtual monotheism where other gods became manifestations of him. With Osiris, Amun–Ra is the most widely recorded of the Egyptian gods."
© Haydn Thompson 2020