July 22, 2011, 3:25pm: A car bomb is detonated by 32-year-old Anders Breivik in Oslo’s government district, in front of Prime Minister Jens Stoltenberg’s office. The explosion kills eight and injures hundreds. Stoltenberg was not present when the explosion occurred.
5:18pm: Breivik, wearing a police uniform, lands on Utoya Island, 38km northwest of Oslo, where members of the Norwegian Labour Party’s youth group are gathered at a summer camp.
5:24pm: Norwegian police first learn of the shootings at Utoya.
6:01pm: Breivik calls Norway's emergency telephone number, saying he wishes to surrender. He then resumes the killings.
6:26pm: A SWAT team lands on Utoya, after more than an hour of Breivik shooting.
6:34pm: Breivik is arrested by police without resistance after shooting to death 69 people. Breivik later explained the massacre as an act of self-defence against a "Muslim invasion of Europe".
July 25, 2011: About 200,000 people attend a "rose march" in Oslo to commemorate the victims of the attacks. Prime Minister Stoltenberg calls Breivik's attacks the worst act of violence that the country has faced since World War II.
March 15, 2012: Oeystein Maeland, Norway's national police commissioner, apologised for the police's slow response to the massacre. "It is hard, knowing that so many lives could have been spared if the perpetrator had been arrested sooner," he said at a press conference.
April 10, 2012: Psychiatrists find Breivik to be legally sane. A previous psychiatric analysis had claimed Breivik was a paranoid schizophrenic.
April 16, 2012: Breivik’s criminal trial begins. Breivik admits to carrying out the bombing and shootings but denies criminal responsibility, saying the attacks were necessary. Prosecutors call for Breivik to be found insane.
April 26, 2012: About 40,000 Norwegians gather in Oslo to sing "Children of the Rainbow", a children's song by Pete Seeger. During his trial, Breivik professed his hate for the song, which he said was a symbol of "cultural Marxism".
June 22, 2012: Breivik’s trial ends with a walkout by victims' families after Breivik's courtroom remarks that his attacks were necessary. His lawyers argue that Breivik is sane.
August 13, 2012: The Gjorv Report is released, which found that police could have prevented the bombing and could have arrived on Utoya Island sooner. Afterwards, Maeland resigned.
August 24, 2012: The court ruled that Breivik is sane and sentenced him to 21 years in prison. The court can continue to hold prisoners it regards as continuing to pose a danger. Norway has no death penalty.