The trial of Abu Walaa, named by authorities as Ahmad Abdulaziz Abdullah A., opened Tuesday, with proceedings due to be spread over 29 trial days until next January. Also facing charges of supporting IS are four co-defendants.
Armed police guarded the Upper Regional Court located in the historic city center of Celle, near Hanover, where the trial is taking place.
Abu Walaa, 33, nicknamed the “faceless preacher” for showing only his back to the camera in propaganda videos, arrived in Germany in 2001 as a teenager.
He was arrested last November on accusations of recruiting at least 16 young men for IS.