Erol İncedal, 26, who has Alevi and Kurdish roots, is a law student accused of plotting a Mumbai-style Islamist attack and targeting the former prime minister Tony Blair.
He was arrested on 13 October last year in a Black Mercedes that was stopped by armed police in Aldgate.
His trial, which began last week, is the subject of intense scrutiny in Britain because significant portions of the evidence will be heard in secret and journalists will not be permitted to report their contents.
After evidence was heard at the Old Bailey, newspapers in Britain were able to reveal that Mr İncedal was born in Istanbul to a Kurdish father who came from the village of Kürecek, near Malatya in eastern Turkey.
After his father, a communist, died when he was just six weeks old, Erol İncedal took some members of the family to Britain, leaving some children behind in Turkey on the understanding they would follow later.
One of the children, Mr İncedal’s elder sister, joined the PKK, a Kurdish militant group fighting for independence from Turkey that has no links to religious extremism. She was killed while fighting for the PKK in the early 1990s, the Old Bailey heard.
According to The Times, he told the court that he became interested in religion around the age of 13 or 14. He continued: “I was at school and I didn’t know anything about Islam, I would just say I was Muslim because I was from Turkey.
“At lunchtimes we could go out of school so that Muslims could go to the mosque and pray during Ramadan and I would pretend to be Muslim so me and a friend could go and get a kebab and go to the local bookies.
“The guys who were going to the mosque tried to persuade us to join them and we didn’t want them to grass us up so we went.”
Mr İncedal married at the age of 17 and had a daughter with his wife, but the couple had an unstable home life and the marriage caused conflict with his own family.
Media coverage of the trial has been sporadic because evidence is often heard in closed session.
Mounir Rarmoul-Bouhadjar, 26, from south London, the driver of the car in which Mr İncedal was also arrested, has pleaded guilty to possessing a document called “bomb making”. Mr İncedal denies the same charge.