Nigeria government; the leader is elected by popular vote to a maximum of two 4-year terms. In the 28 March 2015 presidential election, General Muhammadu Buhari emerged victorious to become the President of the Federal Republic of Nigeria, defeating then-incumbent Dr Goodluck Jonathan. The president's power is checked by a Senate and a House of Representatives, which are combined in a bicameral body called the National Assembly. The Senate is a 109-seat body with three members from each state and one from the capital region of Abuja; members are elected by popular vote to four-year terms. The House contains 360 seats,
Head of state heads of state, sometimes in addition to another title, such as the Ottoman Sultan. Historically, some theocratic Islamic states known as "imamates" have been led by imams as head of state, such as in what is now Oman, Yemen, and Saudi Arabia. In the Islamic Republic of Iran, the Supreme Leader, at present Ali Khamenei serves as head of state. The Aga Khans, a unique dynasty of temporal/religious leadership, leading the Nizari offshoot of Shia Islam in Central and South Asia, once ranking among British India's princely states, continue to the present day. In Hinduism, certain dynasties adopted a title