Led by 37-year-old "emir" Mohamed Achamlane, the 15 members of Forsane Alizza, who called themselves the "knights of pride", have denied involvement in a terrorist organisation.
Achamlane told the court he had no "terrorist inspiration" and only wanted to defend Muslims against mounting Islamophobia in France.
The group was formed in 2010, gaining attention for organising protests against the government's decision to ban veils in public.
It was disbanded two years later by the government, which described it as a "private militia".
"If our demands are ignored, we will consider the government to be at war against Muslims," the message said.