Sudan's former autocratic president Omar al-Bashir, ousted amid a popular pro-democracy uprising last year, faces trial from Tuesday over the military coup that brought him to power more than three decades ago.
Bashir, 76, who is already behind bars for corruption, could face the death penalty if convicted over his 1989 coup against the democratically elected government of prime minister Sadek al-Mahdi.
The Khartoum trial starting at 0800 GMT against him and 16 co-accused comes as Sudan's post-revolution transitional government has launched a series of reforms in hopes of fully rejoining the international community.
Sudan has also pledged to hand over Bashir to the International Criminal Court to face trial on war crimes and genocide charges related to the Darfur conflict, which left 300,000 people dead and millions displaced in a scorched earth campaign against a 2003 insurgency.
It is the first time in the modern history of the Arab world that the architect of a coup goes on trial, although the man dubbed the true brain behind the military overthrow, Hassan Turabi of the National Islamic Front, died in 2016.
"This trial will be a warning to anyone who tries to destroy the constitutional system," said Moaz Hadra, one of the lawyers who led the push to bring the case to court.
"This will safeguard Sudanese democracy. In this way, we hope to bring an end to the era of putsches in Sudan."
Bashir will be in the dock with 10 military personnel and six civilians, including his former vice presidents Ali Osman Taha and Bakri Hassan Saleh, as well as former ministers and governors.
They are all accused of having plotted the June 30, 1989 coup when the army arrested Sudan's political leaders, suspended parliament and other state bodies, closed the airport and announced the putsch on the radio.
Bashir, who was later elevated to the rank of general, stayed in power for 30 years before being overthrown on April 11 last year after several months of unprecedented, youth-led street demonstrations.
Hadra told AFP that Bashir and Saleh "have totally refused to cooperate with the commission of enquiry, but they will be present at the court".
The lawyer said the accused are charged under crimes including Chapter 96 of the 1983 Penal Code, which had been abolished by Bashir, and which carries the death penalty for attempting to destroy the constitutional order.
Hadra said that "this is the first time someone who launches a coup will be brought to justice" in Sudan, which has seen three coups d'etat since its 1956 independence from Britain.
One of the 150 defence lawyers, Hashem al-Gali, charged that Bashir and the others would face "a political trial" being held "in a hostile environment on the part of the judicial system against the defendants".
"In fact, this trial is aimed at the Islamic movement and its sole purpose is to present it as a terrorist movement, but we have prepared our defence and we will prove the contrary," Gali stressed.
He argued Bashir's overthrow of Mahdi took place so long ago that it was beyond the statute of limitations and should therefore no longer be dealt with by a court.
Former police general Salah Mattar, who was head of internal security in 1989, welcomed the trial, recounting how he had anticipated the overthrow.
"I had observed movements and meetings of the National Islamic Front six months before the coup and made a report to interior minister Mubarak al-Mahdi, but he ignored it," Mattar recounted to AFP.
The trial takes place at a time when Sudan's joint civilian-military transitional government is introducing a host of reforms and has relaunched peace talks with rebel groups.
Prime Minister Abdalla Hamdok's administration has recently abolished rules restricting women's movements, outlawed the practice of female genital mutilation, scrapped a law against apostasy and relaxed a ban on alcohol.
Khartoum hopes to soon be taken off the US State Department's list of countries that sponsor terrorism, a significant hurdle to receiving foreign aid and investment.
