Ottoman sultans were the rulers of the Ottoman Empire, which lasted from the late 13th century until the early 20th century. They held absolute power and were considered both political and religious leaders, often referred to as the Caliph in the Islamic world. The sultans were known for their lavish courts and significant contributions to art, architecture, and culture. The first sultan was Osman I, who founded the empire, and the last was Mehmed VI, who reigned until the empire's dissolution in 1922. Sultans were often supported by a complex administrative system, including the viziers, who helped govern the vast territories of the empire.