Michael Adebolajo has said that whilst growing up in Romford, the "vast majority" of his friends were white British, and one, Kirk Redpath, joined the Army and was later killed in Iraq.
Adebolajo said: "I hold Tony Blair responsible for his death."
He said his favourite teacher at school was the first person to teach him about Adolf Hitler.
He told the court it showed him that "there are some very wicked people in the world".
The 28-year-old was raised as a Christian.
One of the men accused of murdering soldier Lee Rigby has told a jury "my religion is everything".
Michael Adebolajo, 28, began giving evidence at the Old Bailey today, surrounded by five security guards in oak-pannelled Court Two.
He and Michael Adebowale, 22, are accused of murdering Fusilier Rigby by running him down with a car and then hacking him to death with a meat cleaver and knives near Woolwich Barracks in south east London on May 22.
The soldier's relatives sat feet away as Adebolajo spoke to the court.
Adebolajo said he converted to Islam in his first year at Greenwich University.
The court heard that Adebolajo is married and has six children, including a seven-year-old boy.