The ancient Egyptians began calling their king "pharaoh" during the New Kingdom period, which started around the 18th dynasty, approximately 1539 BCE. Originally, the term "pharaoh" (from the Egyptian per ʿaa , meaning "great house") referred to the royal palace itself, but during the New Kingdom, it came to be used metonymically to refer to the king. By the 22nd dynasty (circa 945–730 BCE), "pharaoh" had been adopted as an epithet of respect for the king, although it was never the king’s formal title in official documents