Viziers was the highest official in Ancient Egypt to serve the king, or pharaoh during the Old, Middle, and New Kingdoms. Vizier is the generally accepted rendering of ancient Egyptian tjati, tjaty etc., among Egyptologists.
The role of the Vizier in Ancient Egypt was an extremely important one, equivalent to a Prime Minister. He was the highest court official and the deputy of the Pharaoh. Successful ministers and especially the vizier, were rewarded by large grants of land from the royal domain. The vizier therefore became extremely wealthy. The vizier wielded great power in Egypt and was both feared and respected. The Egyptian name for a vizier was 'tjaty'. During periods of Ancient Egyptian history a vizier was made a god and another vizier became Pharaoh.
Egyptologist believe that the title may have been present from the beginning of the Pharaonic period and in fact there is some evidence that a vizier was depicted on the Narmer palette.