Sadiq al-Mahdi (; 25 December 193526 November 2020), also known as Sadiq as-Siddiq, was a Sudanese political and religious figure who was Prime Minister of Sudan from 1966 to 1967 and again from 1986 to 1989. He was head of the National Umma Party and Imam of the Ansar, a Sufi order that pledges allegiance to Muhammad Ahmad (1844–1885), who claimed to be the Mahdi, the messianic saviour of Islam. Personal life Sadiq al-Mahdi was born on 25 December 1935 in Al-Abasya, Omdurman, Sudan. He was the paternal grandson of Sayyid Abd al-Rahman al-Mahdi, founder of the Umma Party, and great-grandson of Muhammad Ahmad, the Sudanese sheikh of the Ansar and Mahdi who led the Mahdist War to reclaim Sudan from Anglo-Egyptian rule. He was also the paternal uncle of Sudanese-British actor Alexander Siddig. Sadiq al-Mahdi married twice and had ten children, including a son named Siddig after his grandfather al-Imam al-Siddiq, born in 1968, who is now a leader in National Umma Party, and a daughter, Mariam, who is the leader of the National Umma Party. Political life Sadiq al-Mahdi was Prime Minister of Sudan on two occasions: first briefly in 1966–67 and second from 1986 until his ousting on 30 June 1989. First term as prime minister (1966–1967) After the 1965 elections, a coalition government was formed between the National Umma Party and the National Unionist Party. Muhammad Ahmad Mahgoub of the Umma party became Prime Minister, and Ismail al-Azhari of the NUP became president. However, this coalition collapsed in October 1965 after the two parties failed to agree on control of the Ministry of Foreign Affairs. In July 1966, Prime Minister Mahgoub resigned after a parliamentary vote of censure. Mahgoub's resignation split the Umma party into two factions: the opposition faction was led by Mahgoub and endorsed by Sadiq's uncle, the Imam al-Hadi al-Mahdi, while Sadiq led the faction that was willing to work with the NUP. As Sadiq's faction was larger, he became Prime Minister with NUP support. He supported regional development and greater autonomy for the southern provinces. These proposals were unpopular with many educated Sudanese civilians and army officers. In May 1967, Sadiq lost the support of his coalition partners, and Mahgoub returned as Prime Minister in a coalition with the National Unionist Party and the People's Democratic Party. In the 1968 elections, Sadiq's faction won more seats than Mahgoub's faction, but Sadiq lost