In name, Ethiopia was a constitutional monarchy between 1931 and 1974, but sovereignty was vested solely in the emperor, a hereditary monarch. The ruler appointed the prime minister, senators, judges, governors, and mayors. The emperor was assisted by the Council of Ministers and the Crown Council, whose members he appointed.
After the military takeover in 1974, the parliament was dissolved and the provisional military government (PMG) established. The PMG assumed full control of the government and continued to rule through its provisional military administrative council, also called the Dergue, whose chairmanship Mengistu seized in February 1977. Government decisions were made by Mengistu on an ad hoc basis, sometimes in consultation with members of the Dergue's Standing Committee. Control over government ministries was maintained by assigning Dergue representatives to oversee their operations. The Commission for Organizing the Party of the Working People of Ethiopia acted as the Dergue's political arm.
The constitution approved by referendum on 1 February 1987 declared Ethiopia to be a people's democratic republic. A national assembly (Shengo), with 835 members chosen by proportional representation for the various nationalities, theoretically had supreme power. The president, who was elected to a five-year term by Shengo, acted as chief executive and commander-in-chief of the armed forces and nominated and presided over the cabinet and the state council, which had legislative power when the Shengo was not in session. The president also appointed top officials of the Worker's Party of Ethiopia (WPE), which was called the leading force in the state and society. The assembly held its first meeting on 9 September; the next day, it elected Mengistu president. It also redrew the political map, creating five "autonomous regions" in order to weaken the appeal of the independence movements. It failed. Despite the trappings of representative government, all power remained in Mengistu's hands. He was head of state and government, leader of the only party and commander of the armed forces.
After Mengistu's defeat in May 1991, a transitional government was established, under the leadership of the Ethiopian People's Revolutionary Democratic Front, a coalition of parties opposed to the Dergue and led by President Meles Zenawi. Elections for a constituent assembly were held in June 1994. A new constitution was drafted, providing for a directly elected president, a bicameral legislature, regional autonomy with the right to secede, and a nine-state national structure. Elections to the newly established Federal Parliamentary Assembly were held in 1995; they resulted in a huge victory for the EPRDF owing to opposition boycotts. In the May 2000 elections, Zenawi's coalition gained 368 of the 548 seats in the Council of People's Representative. Next presidential elections were scheduled for October 2007, and parliamentary elections were scheduled for May 2005.
The Federal Parliamentary Assembly has two chambers. The Council of People's Representative (Yehizbtewekayoch Mekir Bet), the lower chamber, has 548 members, elected for a five-year term in single seat constituencies. The Council of the Federation (Yefedereshn Mekir Bet) or upper chamber has 117 members chosen by state assemblies to serve five-year terms.