The High Court has quashed the original accidental death verdicts returned on 96 Liverpool fans who died in the Hillsborough disaster.
Fresh inquests have been ordered by the Lord Chief Justice, Lord Igor Judge, following an application from the Government's top law officer.
Dominic Grieve, the Attorney General, made the application last week after an independent report highlighted attempts by the emergency services to shift blame on to fans for the tragedy, which happened at the FA Cup semi-final between Liverpool and Nottingham Forest on April 15, 1989.
The quashing of the original inquest verdicts has come on the same day that Home Secretary Theresa May announced a new police inquiry into the disaster.
Families of the victims, who attended Wednesday's hearing in London, are hoping that both developments will mark a significant move towards achieving justice.
Trevor Hicks, of the Hillsborough Family Support Group, said the quashing of the inquest verdicts was "a huge step for the families".
A report into the disaster, published by the Hillsborough Independent Panel in September, produced new medical evidence that raised major questions of the original 1991 inquests conducted by coroner Stefan Popper.
Dr Popper did not consider any evidence collected after 3.15pm on the day of the tragedy, ruling that none of the victims could have been saved after that time.
But the independent report - which also cleared fans of any blame for the disaster - established that 41 of the supporters who died might have been saved.
Campaign groups have long maintained that Dr Popper's original verdicts of accidental death prevented a proper investigation into the events at Hillsborough that day.
In making his decision to quash those inquest verdicts, Lord Judge said there had been "deliberate misinformation surrounding the disaster".
He added: "There has been a profound and palpable belief that justice had not been done, and it is clear there are sound grounds for this application."
The judgement was applauded in court by the families of some of the victims. Speaking outside the court, Mr Hicks, who lost his daughters Victoria and Sarah in the disaster, welcomed the decision.
He said: "We're obviously delighted. We thought this would be the result. We've actually got it now.
"It is clear that justice is on its way. It's a huge step for the families, and I think a lot of us are going to have a much happier Christmas."
Kenny Dalglish, who was Liverpool's manager at the time of the Hillsborough disaster, said on Twitter: "Two fantastic results today for the Hillsborough families. Your support has been unbelievable."
Ian Ayre, Liverpool's managing director, said in a statement on the club's website: "Everyone at Liverpool Football Club remains committed to supporting the fight for justice and we hope that every person affected by this can take some comfort from today's announcement."
Joe Anderson, the mayor of Liverpool, added: "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 versions have been quashed.
"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."