The British High Court has quashed the original accidental death verdicts into the deaths of 96 Liverpool fans at Hillsborough 23 years ago.
The supporters died in a crush at Sheffield Wednesday's Hillsborough stadium on 15 April 1989 as Liverpool met Nottingham Forest in an FA Cup semi-final.
Today, Chief Justice Lord Judge and two other judges in London ordered fresh inquests following an application by the Attorney General Dominic Grieve.
The new investigation could lead to criminal prosecutions - and for serving police officers it could also lead to misconduct proceedings.
Lord Judge described what happened in 1989 as "catastrophic".
Referring to the families, he said there had been a "profound, almost palpable belief that justice has not been done and that it cannot be done without and until the full truth is revealed".
"We must record our admiration and respect for their determined search for the truth about the circumstances of the disaster and why and how it had occurred, which - despite disappointments and setbacks - has continued for nearly quarter of a century."
More than 40 relatives of the 96 victims were in court to attend the hearing this morning.
At least six MPs were also present.
Mr Grieve said the "horrific" events at the stadium were well known, adding: "They were seen by millions on television as the tragedy unfolded and by many of the spectators at the stadium itself."
He said that in the months and years that followed, the events that led to the tragedy "have been the subject of numerous investigations and inquiries".
This year's Hillsborough independent panel report triggered a raft of apologies from the likes of Prime Minister David Cameron and former Sun editor Kelvin MacKenzie.
Mr MacKenzie was the editor of The Sun when it ran a front page story blaming fans for the disaster.
It also ultimately led to the resignation of West Yorkshire Chief Constable Sir Norman Bettison, who was a chief inspector with South Yorkshire Police at the time.
"This is a watershed moment on the road to justice for the families of the 96"- Joe Anderson
The panel's report found there were clear operational failures in response to the disaster and up to 41 fans could potentially have survived.
It also found the then chief constable of South Yorkshire, Peter Wright, and his officers, with the help of local Tory MP Irvine Patnick, sought to cover up the failing.
Mayor of Liverpool Joe Anderson said: "This is a watershed moment on the road to justice for the families of the 96, and I share their overwhelming relief that, after 23 very painful years, the inquest verdicts have been quashed.
"It is the only right and proper decision that the High Court could make in the wake of the overwhelming and compelling evidence uncovered by the Hillsborough Independent Panel.
"We must all keep up the pressure that has driven the momentum over the last few months to make sure that the families get the justice they deserve.
"I also welcome the new police investigation, which we all hope will result in those that played a role in causing the disaster and the monumental cover-up are brought to account."