Mohammed Abdallah, 26, travelled to Syria with the help of his younger brother, Abdalraouf, who was convicted last year of assisting others in committing acts of terrorism.
Abdallah was outed as an Isis fighter in 2016 when a defector from the terror group passed files to Sky News that listed him as a specialist sniper with expertise with the “Dushka”, a Russian heavy machine gun.
On Thursday, Abdallah, from Moss Side in Manchester, was found guilty at the Old Bailey of possessing an AK47 gun, receiving £2,000 for terrorism and membership of Isis.
The trial heard how he had travelled to Syria in 2014 with Nezar Khalifa, 28, also from Manchester, to meet two others from the city: the former RAF serviceman Stephen Gray, 34, and Raymond Matimba, 28. Abdallah was arrested by counter-terrorism police when he returned to the UK in September 2016.
His trial had been delayed in the wake of the attack on the Manchester Arena for fear that a jury would be prejudiced by reports of his links with the bomber Salman Abedi, who attended the same mosque as the brothers.
Sentencing Abdallah on Friday, Mrs Justice McGowan said she accepted that he had acted under the influence of his brother “to some extent”.
“There is no evidence of possession of extremist propaganda material. The evidence of your mindset is to be found in your actions,” she said. “Your commitment to violence abroad is clear and you have not shown any sign of changing your views or attitudes.”
The court heard that Abdallah had a below-average IQ of 68 and had a previous conviction for assaulting a police officer while drunk or high in 2013.
The brothers, who had moved to Manchester from Libya as children, had joined the Tripoli Brigade fighting against the Gaddafi regime in 2011. Abdalraouf was shot in battle and paralysed from the waist down.
In 2016, Abdalraouf, now 24, was found guilty of assisting others in committing acts of terrorism and of terror funding, and jailed for five and a half years.
Greater Manchester police has refused to confirm a connection between Abedi and the Abdallah brothers, who were all born to Libyan parents, but the suicide bomber is reported to have visited Abdalraouf in HMP Altcourse, Liverpool, in the months leading up to the attack.
Giving evidence during his trial, Abdallah denied swearing allegiance to Isis, saying he went to Syria only to help deliver $5,000 (£3,740) to the poor and someone else must have filled out the form without his knowledge.
He said: “It’s true I refused to swear allegiance. They did send me to prison. I was threatened with being beheaded. I was shot at. I was hit. I had bruises and a black eye.”
To contact the author of this story: theguardian