Aabid Khan and Sultan Muhammad are cousins
A man described as a "key player" in the radicalisation of young Muslims has been sentenced to 12 years in prison.
Aabid Khan, 23, from Bradford, was one of three men convicted at Blackfriars Crown Court of possessing or making documents promoting terrorism.
Khan's cousin Sultan Muhammad, 23, also from Bradford, was sentenced to 10 years in jail.
The judge said it was one of the most serious cases of its kind to have come before the courts.
Britain's youngest convicted terrorist Hammaad Munshi, 18, from Dewsbury, will be sentenced next month.
He was just 16 when he was arrested on his way home from school. Police later found a guide to making napalm on his computer.
He was found guilty of making a record of information but cleared of a possession offence. He will be sentenced at the Old Bailey on 19 September.
Former fast food restaurant worker Khan was arrested at Manchester Airport in June 2006 on his return from a trip to Pakistan.
Munshi will be sentenced at the Old Bailey in September
He was found guilty of possessing articles for a purpose connected with terrorism, but cleared of a similar charge.
Muhammad, who was a night sorter for the Royal Mail, was convicted of three similar charges and one of making a record of information likely to be useful in terrorism.
Judge Timothy Pontius said they had not been convicted of planning a specific attack.
But he said the material was "amongst the largest and most extensive ever discovered and thus makes this case one of the most serious of its type to come before the courts".
Much of the material could be described as "offensive propaganda", he said, which gave an insight into people's "fanatical beliefs".
But he said there was a "huge quantity" of material which had precise instructions on how to carry out terrorist activity.
"It is that material ... which was possessed by you for a specific intention, to be used in due course to provide practical assistance in terrorist activity," he said.
This included computer files and manuals about acetone - a component of explosives - and how to make napalm.
Judge Pontius added: "Perhaps most chillingly of all was the vest folder demonstrating in careful, methodical and lethal detail the step-by-step instructions of how to make a suicide bombers' vest or belt packed with ball bearings and explosives."
Khan had addresses of 15 members of the royal family
Twice-married Khan had developed an all-consuming hatred of non-Muslims, the court had previously heard.
The three-month trial heard that when he was stopped at Manchester airport, police found the largest cyber "encyclopaedia" of articles promoting terrorism yet seized in Britain in his luggage.
It included personal information and the addresses of 15 members of the royal family, among them the Queen and the Duke of Edinburgh.
The defendants had used defences of "hoarding", "curiosity" and that the material "belonged to others" to explain the finds.
Khan's father, Sabir, had to be forced from court by security officials as the judge passed sentence after accusing him of being "anti-Muslim" and indulging in "hype".
He punched a reporter to the floor when he was asked his name when he got outside.