Shehzad Tanweer, 22, was born in Bradford but lived most of his life in the Beeston area of Leeds - little over half a mile from his friend, 7 July bus bomber Hasib Hussain.
Tanweer was a sports science graduate whose interests included cricket and ju-jitsu.
Shehzad Tanweer's uncle said his nephew was 'proud to be British'
In 2004, he was arrested for disorderly conduct and cautioned.
In November of the same year he travelled to the Pakistani city of Karachi along with Mohammad Sidique Khan.
Pakistani officials say he was also briefly in the country on at least one other occasion, possibly at the end of 2003.
Reports that he visited the eastern cities of Lahore and Faisalabad have not been confirmed, but his family has said he attended an Islamic school, or madrassa, during this visit.
It has also been claimed that just a few months before the
bombings, Tanweer met a leader of the outlawed radical group Jaish-e-Muhammad, which is said to have links to al-Qaeda.
Along with Khan, he became known to the security services on the
periphery of other surveillance operations.
But as the official report into the 7 July bombings found: "There were more pressing priorities at the time, including the need to disrupt known plans to attack the UK. It was decided not to investigate them further or seek to identify them."
Computer expert Martin Gilbertson has said he warned West Yorkshire police about Tanweer's extremist views when he worked at an Islamic bookshop in Beeston in 2003. The police say they have no record of this.
Tanweer's uncle said his nephew and fellow bomber Khan had spent a great deal of time together in Pakistan before they returned to Britain in February 2005.
Tahir Pervez said: "They used to be up all the night talking to each other
whenever Khan visited Tanweer during this period."
Dec 1982: Born in W Yorks
Apr 2003: Camping trip with fellow bomber Mohammad Sidique Khan and other young men
Apr 2004: Police caution - disorderly conduct
Nov 2004-Feb 2005: Visits Pakistan with Khan
June 2005: Recce visit to London
7 July 2005: Bombs Tube train near Aldgate, killing seven
Source: UK government
Tanweer's DNA, along with that of two other suicide bombers, was found at their bomb factory at 18 Alexandra Grove in Leeds.
Much of the bomb-making equipment was still in place when police raided the property on 12 July 2005.
The families of Tanweer and Hasib Hussain both noticed their hair had been bleached in the weeks before the bombings - this they explained away, saying it was due to chlorine in swimming pools.
The authorities believe this was probably caused by explosive mixtures.
Newspapers quoted friends who said Tanweer was quiet and very religious but did not express an interest in politics.
Shehzad Tanweer was born in Bradford and brought up in Leeds
So how did he become one of Britain's first suicide bombers?
The official report into the 7 July bombings found Tanweer, along with Hussain and Khan would have had the opportunity to attend lectures, watch videos and read material by extremists, but that it was not known if any did to a significant extent.
"Their indoctrination appears to have taken place away from places with known
links to extremism," it said.
The report also revealed the existence of rumours suggesting that Tanweer, along with Khan, had been to Afghanistan for "violent
Another uncle, Bashir Ahmed, 65, said the family was "shattered" by the revelation that he appeared to have been involved in the bombings.
"He was proud to be British," he said. "He had everything to live for. His parents were loving and supportive.
"He was a very kind and calm person. He was respected by everyone."
Neighbours described the graduate, who studied at Leeds Metropolitan University, as a "good Muslim". Others said he was a "nice lad" who could "get on with anyone".
Yet Shehzad Tanweer detonated a bomb on a Circle Line train between Aldgate and Liverpool Street stations killing himself and seven people, and injuring more than 100.
The remains of Tanweer were buried near his ancestral town of Samundari in Punjab province, Pakistan, in October 2005.
On 6 July 2006, the eve of the first anniversary of the London bombings, a video allegedly showing Tanweer was aired by al-Jazeera television.
In the video, speaking in a Yorkshire accent, he said: "What you have witnessed now is only the beginning of a string of attacks that will continue and become stronger."