In September 1983, president Gaafar Nimeiry introduced Islamic sharia laws in Sudan, known as September Laws (Arabic: قوانين سبتمبر, romanized: Qawānīn Sibtambir), disposing of alcohol and implementing hudud punishments such as public flogging for alcohol consumption and amputations for theft. Nimeiry declared himself the imam of the "Sudanese umma", leading to concerns about the undemocratic implementation of these laws. Hassan al-Turabi (then the attorney general) assisted with drafting the law and later supported the laws, unlike the leader of the opposition Sadiq al-Mahdi's dissenting view.
Nimeiry's alliance with the Sudanese Muslim Brotherhood aimed to end sectarian divisions and consolidate Islamic governance. Despite Nimeiry's assertion that the Sharia laws reduced crime rates, his economic policies, including Islamic banking, led to severe economic issues in Sudan, including high inflation and substantial external debt. This led to his removal in 1985, and the law was frozen during the transition to democracy between 1985 and 1989.
Ultimately, Nimeiry's Islamic policies contributed to the Second Sudanese Civil War in southern Sudan in 1983, ending the Addis Ababa Agreement of 1972, which had granted Southern Sudan regional autonomy and recognised the diversity of the Sudanese society. This shift towards Islamic governance played a crucial role in Sudan's political landscape with multiple parties including the National Islamic Front advocating for Islamic laws during the Omar al-Bashir era between 1989 and 2019.