Giving his profession as "former president of the republic",
Bashir seemed in good physical condition as he appeared in a metal courtroom cage wearing white prison-issue clothes and a medical face mask that he lowered to identify himself.
In footage carried by Sudanese state TV he said he was resident in Khartoum's Kober prison, 76 years old, and had two wives.
Some of Bashir's former associates appeared alongside him at the trial, which had been postponed because of overcrowding at the scheduled opening last month.
Military officers ousted Bashir in April 2019 after months of street protests, leading to a power-sharing agreement between the military and civilian groups.
Tuesday's court hearing came a day after Sudan's transitional leadership signed a peace deal with some of the rebel groups that had battled Bashir's military and allied militias in Darfur.
Bashir is separately facing prosecution over his alleged role in the repression of protests against his rule, and in December was sentenced at another trial to two years in prison on corruption charges.
He is also wanted by the International Criminal Court on charges of alleged genocide, war crimes, and crimes against humanity in Darfur.