Al Hassan was convicted on charges including including torture, rape, and destroying religious buildings.
Al Hassan Ag Abdoul Aziz Ag Mohamed Ag Mahmoud, 46, was convicted on Wednesday on charges including torture, rape and sexual slavery, and destroying religious and historic buildings.
He faces up to life imprisonment when a sentence is handed down at a later date.
Prosecutors said Al Hassan was a key member of Ansar al-Din, an al-Qaeda-linked group that held power in northern Mali in 2012.
He was accused of personally overseeing amputations and floggings while serving as police chief during the period when Ansar al-Din, in collaboration with the main Tuareg rebel group in Mali, seized control of Timbuktu for nearly a year.
Defence lawyer Melinda Taylor told judges that Al Hassan was a member of the Islamic police force who was “obliged” to respect and execute the decisions of the Islamic tribunal.
“This is what the police around the world do,” she said.
However, during the trial, which opened in 2020, prosecutors said Timbuktu citizens had lived in fear of “despicable” violence during Al Hassan’s time.
Women and girls suffered in particular under Ansar al-Din’s regime, facing corporal punishment and imprisonment, the court’s then-chief prosecutor Fatou Bensouda said at the start of Al Hassan’s trial nearly four years ago.
Al Hassan is accused of forcing women and girls to “marry” fighters, with some victims raped multiple times, according to prosecutors, who said he was “personally involved” in flogging women accused of adultery.
In Timbuktu, victims of Ansar al-Din’s crimes are awaiting possible compensation.
“We are waiting and hoping for a judgement that will give us justice,” said Yehia Hamma Cisse, president of a group of victims’ associations in the Timbuktu region.
Al Hassan is the second Malian leader tried at the ICC for destroying religious sanctuaries in Timbuktu, among other crimes. Timbuktu is inscribed on UNESCO’s World Heritage list.
The Hague-based court sentenced Ahmad al-Faqi al-Mahdi in 2016 to nine years in prison, reduced by two years on appeal in 2021.