Vizier (Arab: wazīr, Turkish: vezir, Spanish: visir), originally an old Iranian term, it indicates a high-ranking political minister or adviser. From Persia the position spread to the Arabs, Mongols and Turks. A Grand Vizier ranks like a Prime Minister, often de facto ruling the government.
In Egypt the vizier was in charge of the entire operation of the government and the position was often hereditary; at various times he was also the High Priest.
The chief advisor and administrator of the Pharaoh, was the Tjaty, the Vizier or Prime Minister. The position of tjaty or vizier was in existence by the beginning of the Third Dynasty, the start of the Old Kingdom. The earliest-known holder of the title was named Menka, mentioned on a number of ink inscriptions on a stone vessel found beneath the Step Pyramid of Djoser Netjerikhet. The vizier had authority and power that were second only to the Pharaoh, and sometimes perhaps rivaled the Pharaoh's authority. 
Aladdin deals with a fictional Grand Vizier in the Arabian Nights.
- Trigger, B. G., Kemp, B. J., O'Connor, D., Lloyd, A. B. (1983) Ancient Egypt: A Social History. University Press, Cambridge.