Hassan al-Turabi was a Sudanese politician and scholar. He was the alleged architect of the 1989 Sudanese military coup that overthrew Sadiq al-Mahdi and installed Omar al-Bashir as president. He has been called "one of the most influential figures in modern Sudanese politics" and a "longtime hard-line ideological leader". He was instrumental in institutionalizing Sharia in the northern part of the country and was frequently imprisoned in Sudan, but these "periods of detention" were "interspersed with periods of high political office".

Sadiq al-Mahdi, 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.