The 96 Liverpool fans who died in the Hillsborough disaster were unlawfully killed, the inquests jury has concluded.
The jurors were told they could only reach that determination if they were sure of four "essential" matters concerning the deaths at the 1989 FA Cup semi-final.
They had to be convinced that overall match commander Chief Superintendent David Duckenfield owed a duty of care to those who died in the disaster, and that he was in breach of that duty of care.
Thirdly, they would need to be satisfied that his breach of duty caused the deaths and, fourthly, that it amounted to "gross negligence".
They concluded it was unlawful killing by a 7-2 majority.
The conclusion was greeted with sobbing and cheers at the hearing in Warrington.
The jury also ruled that fan behaviour did not cause or contribute to the tragedy.
27 years to clear the names of 96 people who did nothing wrong.— aidan o'hara (@oharaa) April 26, 2016
The Hillsborough disaster unfolded during Liverpool's cup tie against Nottingham Forest on April 15 as thousands of fans were crushed at Sheffield Wednesday's ground.
Mr Duckenfield gave the order at 2.52pm to open exit Gate C in Leppings Lane, allowing around 2,000 fans to flood into the already packed central pens behind the goal.
The jury also found that both the police and the ambulance service caused or contributed to the loss of lives in the disaster by an error or omission after the crush in the west terrace had begun to develop.
After the key conclusions were delivered, someone in court shouted "God bless the jury".
The jurors were given a round of applause as they left the courtroom.
Lawyers acting for relatives of the victims said the jury's conclusions had completely vindicated the bereaved families' tireless 27-year fight for justice.
The jury of six women and three men gave their decisions on an emotionally charged day for relatives of the 96, many of whom were at court for the conclusion of the longest jury proceedings in British legal history.
Loud applause breaks out after the verdicts.Lots of people hugging, many crying openly.— Tony Barrett (@TonyBarrett) April 26, 2016
Last Wednesday the jury indicated to the court in Warrington that unanimous decisions had been reached on every question apart from question six - unlawful killing.
They were given a majority direction yesterday and quickly indicated they had reached a majority decision on the outstanding question.
The fresh inquests began on March 31, 2014, in a specially built courtroom in Warrington.
The 1991 accidental deaths verdicts from the original inquests were quashed following the 2012 Hillsborough Independent Panel report after a long campaign by the families of the dead.
Dozens of relatives of the victims have attended each of the more than 300 days the court has sat at Bridgewater Place on the Cheshire town's Birchwood Park business park.
At the start of the inquests, the coroner said none of the victims should be blamed for their deaths.
Emotional tributes to each of the 96 were then delivered by family members in the form of personal portraits.
The jurors also found unanimously that policing of the match caused or contributed to a dangerous situation developing at the Leppings Lane turnstiles.
Commanding officers also caused or contributed to the crush on the terrace, the jury decided, as did those senior officers in the police control box when the order was given to open the exit gates at the Leppings Lane end of the stadium.
As families left the building they were met with applause from crowds who had gathered outside the court in support.
Many had arrived wearing Liverpool Football Club scarfs and holding posters and banners of loves one.
Labour MP Andy Burnham, who has supported the families' campaign, said: " This has been the greatest miscarriage of justice of our times.
"But, finally, it is over."
Former Liverpool captain Jamie Carragher tweeted: "Justice finally. #JFT96."
John Aldridge, who was in the Liverpool at Hillsborough, tweeted: "Fantastic to see the reaction of the families outside the court! Very emotional as well.
"The truth is out AT LAST. Take note all the doubters!!"
The victims' families hugged each other and broke down in tears after emerging from the court.
One man shouted "Justice" while two men held up a red scarf that also read "Justice".
Others made emotional phone calls to loved ones. Two women jumped up and down overcome with emotion as they embraced.
Features of the design, construction and layout of the stadium considered to be dangerous or defective caused or contributed to the disaster, the jury decided.
Jurors also found the safety certification and oversight of the stadium also caused or contributed to the tragedy.
They reached the same conclusion in relation to Sheffield Wednesday's management and/or preparation for the semi-final tie and the dangerous situation that developed at the Leppings Lane turnstiles and in the west stand.
However, the jury concluded that the club's conduct on match day may only have caused or contributed to the same situation.
The club's then consultant engineers, Eastwood & Partners, should also have done more to detect and advise on any unsafe or unsatisfactory features the stadium which caused or contributed to the disaster.
Dozens of people outside the court began singing You'll Never Walk Alone before chanting "Justice for the 96" over and over again.