Breivik has said the attacks were necessary to protect Norway from being taken over by Muslims.
He claims he targeted the government headquarters in Oslo and the youth camp to strike against the left-leaning political forces he blames for allowing immigration in Norway.
Dressed in a dark suit and sporting a thin beard along his jawline, Breivik smiled as a guard removed his handcuffs in the crowded court room.
The 33-year-old then flashed a closed-fist salute, before shaking hands with prosecutors and court officials.
In a manifesto he published online before the attacks, Breivik wrote that “patriotic resistance fighters” should use trials “as a platform to further our cause.” Norway’s NRK television will broadcast parts of the trial, but it is not allowed to show Breivik’s testimony.
He had told investigators he is a resistance fighter in a far-right militant group modeled after the Knights Templar — a Western Christian order that fought during the crusades — but police have found no trace of the organization and say he acted alone.
Tore Eikeland, 21, had a promising political career ahead of him Monica Bosei, 45, was also among the victims.
Thick glass partitions were put up to separate the defendant from victims and their families, many of whom are worried that Breivik will use the trial to promote his extremist political ideology.
Simon Saebo’s friends called the aspiring politician “JF Kennedy” President at his school, Simon Saebo, 18, was from Troms in northern Norway.
He was given the nickname amongst his friends as JF Kennedy.
Mother-of-two Monica Bosei had lived on Utoya for 20 years Hanne Kristine Fridtun, 20, is from Stryn, more than six hours north of Oslo. At around 6pm on Friday she called a television station and said she was hiding with around 20 others.
Hanne Kristine Fridtun was known for helping the vulnerable in her community It is thought she tried to swim away from the island.