The trial of former South Sudan Vice President Riek Machar began on Monday in the capital, Juba.
South Sudan: Riek Machar presented in a cage as high-stakes treason trial unfolds
Machar, alongside the coaccused, was presented in a cage inside the courtroom.
The justice authorities said Machar faced criminal charges for his alleged role in an attack on a garrison of government troops earlier this year.
Other charges include murder, conspiracy, terrorism, destruction of public property and military assets and crimes against humanity.
This was the first time Machar appeared in public since he was placed under house arrest in March.
The trial was televised nationally.
Machars's lawyers argued that the court was incompetent and therefore lacked jurisdiction on the matter. They further defended Machar, claiming that he is protected from such persecutions since he is part of the signatories to the 2018 peace deal that brought the end of a civil war that claimed the lives of at least 400,000 people.
Both Machar and President Salva Kiir are not on good terms. Kiir hails from the Dinka, the largest ethnic group, while Machar hails from the Nuer, the second largest.