When did horus merged with Ra?

Horus merged with Ra in ancient Egyptian mythology during the New Kingdom period, around the 16th century BCE. This syncretism represented the fusion of the sky god Horus and the sun god Ra, highlighting their shared attributes and reinforcing the pharaoh's divine right to rule as the embodiment of both deities. The combined form, often referred to as Horus-Ra, symbolized the power of kingship and the sun's life-giving force. This merger reflects the broader trend in Egyptian religion of integrating various deities over time.