It was time of great civil unrest in Northern Ireland in 1972, euphemistically described as "the Troubles". Tensions had been rising in Ulster since 1969 amid an increasing number of bomb attacks by Republican groups.

The bombings were met with a controversial response from the Government in Westminster. British soldiers had been deployed on the streets of Belfast and other cities in Northern Ireland.

Internment - imprisonment with charges being filed - was also introduced and widely seen as an infringement of human rights.

There was a resurgence of Irish nationalism and a flashpoint occurred in the city of Londonderry, or Derry, on January 30 1972.

A civil rights demonstration to protest against the measures imposed attracted some 15,000 marchers, but the occasion turned to tragedy when troops opened fire.

Thirteen protesters died as a result and the episode came to be known as "Bloody Sunday".

The anger at the outrage was felt in Dublin, where crowds rioted in the city and the British Embassy in Merrion Square was firebombed as a result,

An initial judicial investigation led by Lord Widgery cleared the soldiers involved, but even so, it described their actions as "bordering on the reckless".

It was against such a backdrop that the Scottish team refused to travel to Dublin for a rugby international.

There had been threats made against the team.

It was also said that the Scottish Rugby Union (SRU) had apparently been unable to find anyone who was prepared to offer insurance for the team.

One unnamed Scottish player had conceded: "We will play Ireland anywhere but we are not happy about Dublin."

Ireland were captained by fullback Tom Kiernan.

Kiernan, who passed away earlier this month at the age of 83, was the team’s kicker, who proved a particularly important element of a talented side that season. Kiernan insisted that there was little to cause concern to the Scots.

"They’re probably basing it on the press comments on the situation in Ireland and I would say they've probably been misled by a lot of them," Kiernan told Irish television network RTÉ. 

"Naturally if the wives and the players are nervous about coming over and one can understand their feelings," Kiernan suggested.

"I don’t think anyone would be interested in the Scottish players. The authorities here would be 100 per cent behind the match going ahead and would take every precaution to ensure there was no danger to the players."

The Irish Rugby Football Union (IRFU) dispatched a high-powered delegation including President Dom Dineen and coach Ronnie Dawson to Edinburgh to try and persuade the SRU to think again.

"We don't expect any problems, we regard sport as being above politics," Dineen said. 

"The Rugby Union International between Scotland and Ireland is still not on or off following talks between the SRU and the IRFU", A statement said after the meeting.

The Scottish officials met again to discuss certain points which were made, and the idea of a "Dublin Airlift" was suggested in some quarters.

This would have entailed the the Scottish team flying to Dublin on the morning of the match and returning immediately afterwards.

"The idea of it might not be the best solution but it presents a compromise" wrote the Belfast Telegraph’s Nevin McGhee.

The plan came to nothing.

The Scots were said to be uneasy that security could be guaranteed with a crowd of 55,000. There had also been an offer from the French to play the match at the Stade Yves-du-Manoir in Paris, but it was not greeted with any enthusiasm by the Irish rugby authorities.

The SRU met on February 17 in Edinburgh to discuss the matter once more. Its position did not change.

A statement was issued by SRU secretary John Law.

"After due consideration of all the current relevant factors, the Scottish Rugby Union have reluctantly informed the Irish Rugby Union they are unwilling to fulfil the fixture", the statement said.

"I am very pleased it is off," Scotland captain Peter Brown said when the decision had been made. "We weren't looking forward to going at all from the point of view of wives and families."

Dineen admitted, "I am shattered and we are bitterly disappointed.

"We would not have urged them to come if we thought trouble would blow up."

Dineen had hoped that it might be possible to play the fixture later in the season but this too proved impossible.

The decision came as a particular blow to the Irish players partly because the side had begun the tournament in superb fashion.

Although Ireland had five new caps for their trip to Paris, they beat France 14-9 to raise confidence that something special might be in the offing.

At Twickenham, a dramatic late try from veteran centre Kevin Flynn gave Ireland a 16-12 victory which meant that Irish eyes were now targeting a first Grand Slam since 1948.

Mike Gibson registered the disappointment felt by many when the decision became known.

"We had worked hard in the first two matches and were looking forward to playing at home in front of an Irish crowd," Gibson said.

Yet not only was the match against Scotland now in jeopardy but also the game versus Wales.

"Of course we shall have to consider the decision," Welsh Rugby Union (WRU) secretary Bill Clement said.

The WRU met to discuss the problem and the sequence of their deliberations closely followed the pattern of those made by the Scots.

"It was resolved that before coming to a decision on whether the match should be played, the Welsh Rugby Union should meet the Irish Union as soon as possible," said a statement.

At the time, the Welsh team could boast such luminaries as Gareth Edwards, JPR Williams and Gerald Davies.

They too had begun the campaign with victories, against England and Scotland.

This meant that a victory against Ireland would give the Welsh the Triple Crown, a designation to mark beating each of the other three Home Nations.

Davies was among the first to declare that he would not go to Dublin, and had Welsh authorities' support.

"It would take only one stupid person to cause trouble," Davies said. "People are being killed over for no reason at all, and I have to think of my wife and myself," Davies said.

John Taylor, another member of the squad, revealed later that some members of the squad had received threatening letters.

“A couple were unsettled but most of us were quite prepared to go," Taylor insisted.

He later admitted: "It wasn't very encouraging to be shown threatening letters, alleged to have come from the IRA."

Team-mate John Bevan insisted, "I desperately want to play the Irish but I don't mind admitting one would have at the back of one's mind that some incident might blow up."

Ireland's team were left kicking their heels.

Victorious British and Irish Lions captain Willie John McBride considered the 1972 Ireland team the finest he had played for.

"I find it hard to understand the attitude of the Scots and the Welsh," McBride said.

Still the Irish clung to the hope that the matches might be re-arranged to enable the completion of the competition.

"The committee is still hopeful that both matches will be played at Lansdowne Road on later dates," IRFU secretary Bob Fitzgerald said.

The IRFU went so far as to lodge an appeal with the International Rugby Football Board. This was based on the premise that no rugby union was permitted to unilaterally cancel a match.

"I don't think we can force anybody to play these matches," secretary John Hart said.

"It is difficult to identify the bye law under which the Irish are making their appeal."

Matters were further complicated because in those days, the rugby authorities were very strict about ending the season on April 30.

The WRU suggested that the match could be played in Cardiff or at a neutral venue.

"We want to play the Irish but cannot risk putting players or supporters at risk," WRU vice-president Cliff Jones said.

Although alternative venues had been proposed, the IRFU insisted that the match be played in Dublin or not at all.

Not only did the cancelled matches throw the tournament into complete disarray, they also made a considerable impact on the finances of the IRFU It was calculated that the cost was £60,000, around £480,000 ($650,000/€575,000) in modern terms.

"Rugby has everything to lose and nothing to gain from this," French Rugby Federation Albert Ferrasse said.

In fact, France earned great plaudits when they went to Dublin in April. The match was not part of the Five Nations Championship but the fact they travelled at all drew great plaudits.

The Five Nations Championship was never completed, with no champion crowned as both Ireland and the Welsh were undefeated. 

Death threats to players proved a chilling new development in sport in 1972.

In the September of that year, members of the Israeli Olympic team were taken hostage when terrorists infiltrated the Athletes' Village in Munich.

After a tense siege, the terrorists were allowed to take their hostages to the Fürstenfeldbruck airbase.

A rescue attempt went terribly wrong and all the hostages perished - 11 members of the Israeli team and a policeman from Munich died, plus five members of the Black September terror group.

It was an episode which ever since has overshadowed the Munich Games and changed forever the approach to security for major sporting events.

The following year, England were scheduled to play in Dublin in the Five Nations Championship. To great acclaim from the Irish rugby going public, they did play in Dublin.

Irish Taoiseach Jack Lynch was among the 50,000 in the crowd who enthusiastically applauded the England team as they ran out.

The match was won by Ireland who beat England 18-9.

England’s visit passed off without incident in Dublin, but in the north there remained an ever-present threat of bombing campaigns.

In football this had a deep impact on the Northern Ireland team as other teams from across Europe became increasingly disinclined to visit Belfast.

In the course of the next three years Northern Ireland played 18 consecutive away matches.

Eventually football did return.

The occasion was a European Championship qualifying match in April 1975.

More than 25,000 were inside Windsor Park to see Northern Ireland’s players applaud Yugoslavia on to the field.

"People walked out of Windsor Park that night lifted," veteran Irish journalist Malcolm Brodie said.

Even so, the idea that sporting events were immune from the harsher realities of life had been shattered forever.