ON AUGUST 15 1975 at Lancaster Castle Crown Court Mr Justice Bridge handed down 21 life sentences to six men. They were Hugh Callaghan, Patrick Joseph Hill, Gerard Hunter, Richard McIlkenny, William Power and John Walker. Every one of them was innocent of the Birmingham pub bombings for which they had been sentenced.

The pub bombings for which they were convicted had taken place on November 21 1974 at the Mulberry Bush and the Tavern in the Town, both in the centre of Birmingham.

These two explosions were the most serious and damaging attacks in Great Britain since WWII. In total 21 people were killed and 182 people were injured. A third bomb failed to detonate.

Six men were arrested, five Belfast-born, one from Derry and all Roman Catholics. All had lived in Birmingham since the 1960s but their origins alone clearly marked them out as guilty in the eyes of the West Midlands Police.

It was a common joke at the time in the Irish pubs where I drank that the police could arrest you simply for “looking a little bit Irish.”

Five of the six men were arrested as they travelled to Belfast to attend the funeral of IRA member James McDade — clearly another box ticked for those collecting anything resembling evidence.

When the six reached Heysham ferry port they were stopped by a Special Branch unit. Not surprisingly the men did not tell the police why they were visiting Belfast.

As they were being questioned and searched news came through of the pub bombings. The men agreed to be taken to Morecambe police station for forensic tests — tests that it would be said indicated they had handled explosives.

While the men were in the custody of the West Midlands Police they were systematically beaten, deprived of food and sleep and questioned for up to 12 hours without a break. They were threatened with savage police dogs and even subjected to mock execution.

Billy Power, Hugh Callaghan, John Walker and Richard McIlkenny all found it too much. They signed confessions. Paddy Hill and Gerry Hunter refused to sign.

The six men were charged with murder and conspiracy to cause explosions. The men, clearly bruised and beaten, appeared in court for the second time after they had been remanded into custody at HM Prison Winson Green.

A prisoner released from that prison gave evidence that he had seen the six being beaten. No police or prison officers were ever brought to justice.

In the 1980s journalist and later Labour minister Chris Mullin made a TV documentary and published a book making a convincing case for the men’s innocence. Mullins said he had met some of those who were actually responsible for the bombings.

Then home secretary Douglas Hurd MP referred the case back to the Court of Appeal. In January 1988, after a six-week hearing, the convictions were ruled to be safe and satisfactory. The Court of Appeal dismissed the appeals.

Over the next three years a powerful campaign in Britain, Ireland, Europe and the US fought for the men’s release.  Newspaper articles, TV documentaries and books exposed a huge miscarriage of justice.

This campaigning pressure finally forced a second appeal in 1991. It heard new evidence of police fabrication and suppression of evidence. The convincing evidence on both the forced confessions and the fitted up forensic tests caused the Crown to decide not to oppose the appeals.

In 2001, a decade after their release and a full quarter century after their sentencing, the Birmingham Six were awarded compensation ranging from £840,000 to £1.2 million.

No police officer has been punished for their dishonest actions. Superintendent George Reade and two other police officers were charged with perjury and conspiracy to pervert the course of justice, but never came to trial.

In 1993-94 the Birmingham Six recovered an undisclosed amount from both The Sunday Telegraph and The Sun in an action for libel.

No-one has ever been brought to book for the 21 people murdered in the bombings.

The Birmingham Six were by no means the only group of innocent people charged and convicted and later released for supposed IRA bombings.

The Guildford Four — Paul Hill, Gerard Conlon, Patrick Armstrong and Carole Richardson — spent 14 years in prison before their convictions for two IRA bomb explosions in Guildford on October 5 1974 were quashed by the court of appeal in 1989.

In a related case the Maguire Seven were charged with possessing nitroglycerine to make an IRA bomb after the police raided the West Kilburn house of Anne Maguire on December 3 1974.

They were tried and convicted on March 4 1976. Maguire was sentenced to 14 years; her husband Patrick Maguire got 14 years; their 14-year-old son, also named Patrick, four years; another son, Vincent, aged 17, got four years; Anne’s brother Shaun Smyth got 12 years, as did family fried Patrick O’Neill.

The last member of the seven arrested was Giuseppe Conlon, who had travelled from Belfast to help his son, Gerry Conlon, in the Guildford Four trial. He was sentenced to 12 years’ imprisonment.

Conlon, who suffered from serious lung disease, died in prison in January 1980. All the others served their sentences and were released.

The convictions of all the Maguire Seven were quashed in 1991. The court decided that members of the London Metropolitan Police beat some of the seven into confessing to the crimes and withheld information that would have cleared them.

In yet another separate case in 1974, Judith Ward, a severely mentally ill 25-year-old woman was wrongly convicted of the M62 coach bombing. This had happened two years before and killed nine soldiers and three civilians. Ward served 17 years for crimes she did not commit.

In every case the police and judiciary who organised these fit-ups received no punishment. Incredibly, George Oldfield —the man who fiddled the Judith Ward prosecution — was promoted and ended up leading the hunt for the Yorkshire Ripper. Unsurprisingly, that inquiry also ended in a fiasco.