KHARTOUM (Reuters) - Sadiq al-Mahdi, Sudan’s last democratically elected leader and the great-grandson of the messianic figure who fought the British in the 19th century, has died from the coronavirus, the party he led said on Thursday.The two-time prime minister, who was a central figure in Sudan’s political and spiritual life for more than half a century, was being treated in the United Arab Emirates. Current premier Abdalla Hamdok said the 84-year-old was “one of the most important men of thought, politics, literature and wisdom in our country,” as the government declared three days of mourning. Mahdi was last voted into office in 1986, then overthrown three years later in a military coup led by a then-obscure army brigadier, Omar Hassan al-Bashir. Mahdi was imprisoned and forced into exile throughout his career but he staged just as many come-backs and remained influential. His Umma Party was one of the largest opposition groups during Bashir’s 30-year rule. He returned from exile a final time as protests over worsening economic conditions gathered steam in December 2018. Those demonstrations eventually led to Bashir’s overthrow in April 2019. Mahdi’s daughter Mariam Sadiq al-Mahdi, deputy leader of the Umma Party, was among those detained during the protests and has been the party’s most visible political figure in political negotiations since. Opposition parties that were weakened greatly under Bashir’s three-decade rule are now jostling for power with the military during Sudan’s transition, giving the Umma Party a key role in maintaining the balance of power. A successor has not been named. Other family members and party leaders have formed splinter factions over the years.Mahdi was born on Dec. 25, 1935, in Khartoum’s twin city of Omdurman, the former Mahdist capital, and grew up in the last two decades of British imperial rule. Educated by Italian missionaries and later at Britain’s Oxford University, he worked in the finance ministry, eventually won a parliamentary seat and had a brief taste of power when he became prime minister in July 1966 aged 30. The often rapid ebb and flow of Sudanese politics caused him to lose his seat 10 months later and he was arrested in a purge of political parties in 1969 when military man Jaafar Nimeiri seized power. After fleeing Sudan he tried to return at the head of an armed attempt to unseat Nimeiri. He failed in his attempt but Nimeiri was removed by the army in 1985. Mahdi was voted prime minister a year later. Mahdi’s supporters said he combined moderate views with hereditary spiritual authority derived from the Ansar, a groupfounded by his ancestor “the Mahdi,” or messiah. The Mahdi led an insurgency against colonial rule in the late 1800s. Critics highlighted Sadiq al-Mahdi’s failure to convert his promise as a youthful, modernising figure into building a democratic state. They pointed to his second government’s failure to cement a political transition, end a civil war with the south or reverse an economic crisis in which high prices drove mass protests. “Over his long years in politics, he expressed his commitment to democracy, human rights, social justice, and the quest for liberation, and in this he succeeded a lot and failed a lot, which made him a controversial figure,” said Abdelwahid Ibrahim, a UK-based Sudanese analyst. Slideshow ( 3 images ) Last month, Mahdi’s family said he had tested positive for COVID-19. He was transferred to the UAE for treatment a few days later following a brief hospitalisation in Sudan. News of his death prompted an outpouring of condolences from across the political spectrum. The Umma Party said he would be buried on Friday morning in Omdurman.