In September 1983 President Nimeiry imposed sharia as the law of the whole of Sudan, including the largely non Muslim south, by presidential decree. The September Laws introduced hudud penalties, and amputations and floggings were carried out publicly. The decision reopened the civil war that had been settled in 1972 and is generally regarded as the single act that made the eventual separation of South Sudan inevitable.
Mahmoud Mohamed Taha was a Sudanese engineer, independence activist and religious thinker who led a movement known as the Republican Brothers. His argument, set out in The Second Message of Islam, distinguished the earlier Meccan revelation, which he read as the universal and permanent message, from the later Medinan revelation, which he read as legislation for a particular society at a particular time. On that reading the specific legal provisions applied in the name of sharia were historically bounded rather than eternal, and a modern Islamic society should be governed by the Meccan ethic instead. He opposed the September Laws directly and publicly.
He was tried, convicted of apostasy and hanged in Khartoum in January 1985, aged seventy six. Nimeiry fell three months later. Taha's execution remains the reference case in Sudanese arguments about religious freedom, and his work continues to be read.
The apostasy offence, carried into the 1991 criminal code, was repealed by the transitional government in 2020 as part of a wider package that also ended public flogging for certain offences and allowed non Muslims to consume alcohol. The coup of 2021 and the war that followed have left the standing of those reforms unsettled.