"The police pulled out quite suddenly and the troops, armed with machineguns, stood in a line across the mouth of William Street. Their appearance was clear proof we had won the battle, that the RUC was beaten. That was welcomed. But there was confusion as to what the proper attitude to the soldiers might be. It was not in our history to make British soldiers welcome . . ."

The time was 5 p.m. The date was August 14th, 1969. Eamonn McCann was standing behind the barricades in Derry's Bogside during what is now infamously known as the Battle of the Bogside. "The arrival of the British troops represented the greatest defeat for the Unionist government but not yet a victory for us, 30 years on," says McCann.

The Battle of the Bogside started two days earlier, at 3 p.m., following the annual Apprentice Boys' parade, which had attracted up to 15,000 Protestants. Catholics feared the police and the despised B Specials would run amok in Derry, and were determined to defend themselves. The Apprentice Boys' parade had always been a focus of Catholic resentment, often ending in violence and even death.

Everyone knew violence would erupt at the parade, but the British government faltered on taking a decision. Following a meeting between the British Home Secretary, James Callaghan, and Maj James Chichester-Clark, the Northern Prime Minister, The Irish Times on August 12th reported "no change since last week in position of troops in the North, either physically [towards Derry] or politically [towards use in crowd control]".

The decision was left to the Home Affairs Minister in Belfast, Mr Robert Porter. He ruled that the parade could go ahead.

For three days and two nights violence flared between Bogsiders and the police. The Battle of the Bogside had begun, with violence spreading to other parts of Northern Ireland. The RUC fired 161 grenades of CS gas and 1,091 plastic bullets into the Bogside; Catholics replied with petrol-bombs and stones, shocking the world.

The Taoiseach, Mr Jack Lynch, announced on August 13th that Army field hospitals would be set up along the Border to treat Catholics. He appealed to the British government to set up a UN peacekeeping force, much to the annoyance of Protestants, as articulated in the Belfast Telegraph on August 14th. The newspaper dubbed the comments "silly and provocative".

As the shock waves reverberated throughout Whitehall at the televised pictures of Catholics in Derry in confrontation with the police, the British government acted.

Events were to unfold on August 14th with military precision. At 1.30 p.m. the Inspector General of the RUC, Anthony Peacocke, telephoned the Home Affairs Minister at Belfast, Robert Porter, to ask for military help. At 3 p.m. Maj Chichester-Clark telephoned Downing Street, making a formal request for troops. Permission was granted by the British Labour Home Secretary, James Callaghan, and at 5 p.m. 300 soldiers of the Prince of Wales Own Regiment marched into Derry. The GOC in Northern Ireland, Lieut Gen Sir Ian Freeland, assumed control to "restore order".

Mr Paddy Doherty, vice-chairman of the Derry Citizens Action Committee, climbed over barricades in William Street through tear-gas and smoke towards barricades erected by British troops. Through a loudhailer he appealed for the senior officer to come forward.

There was no reaction. Then, according to newspaper reports, "in desperation Mr Doherty pleaded: `In the name of God and for peace in this city, come forward'." The senior officer came forward and, after a meeting, Mr Doherty returned, telling jubilant Bogsiders: "You have won a magnificent victory, and let us not spoil it."

The arrival of British troops was greeted with jubilation by Catholics, who viewed it as a sign that the RUC had been defeated, and the images of smiling nationalists 30 years ago still linger in the memory of many.

Tea, soup and sympathy were dispensed by Catholic women on a regular basis to the soldiers as they manned "peace lines" of barbed wire they had erected to separate the Protestant and Catholic areas. The Irish News said that while the introduction of British troops was "a drastic step . . . If the presence of troops means the withdrawal from Derry of the RUC riot squads and the hundreds of armed Orangemen . . . it may be the first step along the road to peace."

Although an eerie calm was restored to Derry within hours of the troops' arrival, Belfast witnessed the worst violence it had ever seen on August 14th/15th. Ten civilians were shot dead, including nine-year-old Patrick Rooney, who was killed by RUC fire as he lay asleep in his home. In total, 1,505 Catholic families were intimidated out of their homes in Northern Ireland during July, August and September 1969, compared to 315 Protestant families.

On August 15th members of the 3rd Battalion, Light Infantry took up duty in west Belfast and erected barbed-wire barricades to separate Protestant and Catholic areas. The "peacelines" were later to become a more permanent fixture.

The emotion felt by Catholics was expressed in a report by the Irish News. A resident from the staunchly republican Ardoyne area told a reporter: "The British troops were given a splendid welcome and the residents of Ardoyne felt relief at the sight of them, and relationships with these soldiers has been tremendous up to now.

"Let us hope that this will continue to be the case despite the odd rumour that petitions are being given out to get rid of the troops . . . The people who are behind these petitions had their chance in the past to do something for the area and lost it . . ."

But the honeymoon period was shortlived and it wasn't long before the "tea, soup and sympathy" for soldiers dried up. The end of 1969 marked the beginning of the Troubles and a litany of murders in the 1970s.