A vizier is a high-ranking political advisor or minister in various historical Islamic states, particularly during the Abbasid and Ottoman empires. They were responsible for overseeing government administration, implementing laws, and advising the ruler, often holding significant power and influence in the decision-making process. Viziers typically managed various departments, such as finance, military, and justice, and were crucial in maintaining the stability of the state. Their role was similar to that of a prime minister in modern governments, and they often acted as intermediaries between the ruler and the people, ensuring that the ruler's policies were effectively executed.