In a court case begun this week that is expected to take 12 days, the men ranging from 23 to 32 years of age, are being charged with ganging up on the victim one night in August 2011.
The prosecution maintains the attack took place in Geneva’s Plainpalais neighbourhood after the group ambushed the man in a retail gallery.
They surrounded him and proceeded to kick, punch and strike him with knives and sabres, according to the allegation.
The victim fell to the ground but managed to get up and escape.
He suffered injuries including one to the face that left a large scar on his forehead.
Those charged are of Arabic origin, bachelors without profession and without a fixed address, according to a report from the ATS news agency.
Most of them are living in Switzerland without authorization, the report said.
Meanwhile, the victim, who was known to police for break-ins and illegal drug cases, has the same profile as his alleged attackers, ATS said.
The prosecution charges that the attackers acted with a “noticeable absence of scruples” while showing a “certain contempt” for the life of the man they injured.
The accused deny the charges, with one of them alleging that he was not even present when the incident occurred.