A court in Norway has decided that Anders Breivik was sane when he killed 77 people in bombing and shooting attacks on July 22, 2011.
The panel of five judges, who were unanimous in their verdict, sentenced Breivik to the maximum prison sentence of 21 years, with a minimum term of 10 years.
However, such sentences can be extended under Norwegian law, as long as an inmate is considered dangerous.
Breivik smiled as he heard the verdict. He had previously stated that to be declared insane would be a fate "worse than death".
ITV News' Europe Correspondent Emma Murphy reports from Oslo, Norway:
Breivik was allowed to speak briefly after the ruling to confirm whether he intended to appeal.
He was cut off swiftly by the judge when he apologised to "all militant nationalists in Norway and Europe" for not killing more people.
The director general of public prosecutions also confirmed that the prosecution would not appeal the ruling, meaning that the court case has been brought to an end.
Following the announcement of court's verdict, lead judge Wenche Elisabeth Arntzen described how they reached their conclusions:
During his trial, court-appointed psychiatrists assessed Breivik and had made recommendations to the panel of judges.
There had been a lot of debate over Anders Breivik's state of mind when carried out his deadly attacks in Oslo and on Utoya Island.
Two teams of psychiatrists who examined Breivik has reached different conclusions.
The first found Breivik to be insane. They concluded he was a paranoid schizophrenic and was psychotic at the time of the crime.
However, a recent report by forensic psychiatrists Agnar Aspaas and Terje Toerrissen concluded that Breivik was sane.
They also said that he did not exhibit any signs of psychosis during their assessment.
Explaining the conflicting reports, Terje Toerrissen said: "We had additional information, we had more time and we had also done a lot of psychometric testing which goes thoroughly through all sides of the diagnosis."
Tore Sinding Beddekal was one of the survivors of the mass killings carried out by Anders Breivik on Utoya island.
He says he is "happy and relieved" following the court's decision to declare Breivik sane and jail him for his crimes.