Yassin Hassan Omar, the Warren Street bomber, arrived in Britain from Somalia aged 11 in the company of two older sisters and a cousin. He lived with his elder sister until she married a man who took a dislike to him.

Omar’s sister passed him into the care of social services and in 1993 he was placed with Stephen Lamb and Bernice Campbell, experienced foster parents, in Winchmore Hill, North London. They looked after Omar for six years while he attended Aylward School, Edmonton, where he took GCSEs, and then Enfield College. Mr Lamb told the court that Omar was “always very pleasant” but, as he became older, had difficulty with women telling him what to do.

“His sisters wouldn’t be able to discipline him because he was male and of higher social standing,” Mr Lamb said in a statement to police read out in court. Ms Campbell, who is now dead, “had reservations” about Omar. Mr Lamb said: “He wasn’t comfortable with rules, boundaries, if they were set by her.”

In 1999, when Omar turned 18, Mr Lamb and Ms Campbell were no longer allowed to care for him. He was given a council flat on the ninth floor of Curtis House, a tower block in New Southgate.

Lonely and lacking adult guidance, Omar dropped out of college, where he had been studying science, and became increasingly interested in extremist doctrines. Their apparent ability to provide an Islamic answer to all of life’s difficulties offered him a sense of purpose.

The flat was the centre of Omar’s world and open house for his friends. He often made them watch his Islamist propaganda videos and tried to convert nonMuslims, succeeding at least temporarily in persuading Matthew Dixon and Steven Bentley to follow his faith.

No 58 was the obvious place for Ibrahim and Omar to use as their base. There, on the kitchen stove, they reduced hundreds of gallons of liquid hydrogen peroxide to create a concentration of the chemical that would explode. On July 17, 2005, four days before the planned suicide bombings, Omar married, at a ceremony in Finchley mosque, the girl whom he had been seeing for a short while. He had previously argued with the imam who carried out the ceremony over the issue of suicide bombings, but later apologised. The wedding, which his new wife was not required to attend, was carried out at a few hours’ notice.

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