One of the men, Munir Farooqi, 54, received four life terms.
Farooqi, Israr Malik, 23, and Matthew Newton, 29, were arrested after undercover police officers infiltrated religious booths set up in Manchester and discovered the three were attempting to convince vulnerable men to travel to training camps abroad, where they would learn to "fight, kill and die" in a jihad against coalition forces, The Guardian reported Friday.
Prosecutors said Farooqi used his experience fighting with the Taliban as a "tool of recruitment" to run the "Manchester recruitment center" from Islamic bookstalls in the city.
Farooqi was convicted of preparing for acts of terrorism, three counts of soliciting to murder and one count of dissemination of terrorist publications.
Malik and Newton were convicted on lesser charges.
"These men were involved in an organized attempt in Manchester to recruit men to fight, kill and die in either Afghanistan or Pakistan by persuading them it was their religious duty," Detective Chief Superintendent Tony Porter said.
"That is not an expression of religious freedom, but a concerted effort to prepare people to fight against our own forces abroad," he said.
"In law, that is terrorism."