For the residents of the normally quiet village of Clontibret, it was a startling sight as the darkened main street was taken over by a mob, some wearing masks and carrying cudgels.
Soon, the word "invasion" was used to describe the 1986 incursion by loyalists led by Peter Robinson, one designed to show gaps in Border security.
The numbers involved were exaggerated. Some said 500. However, far fewer than that had arrived in the Monaghan village in a convoy of cars along an unapproved cross-Border road from Keady, Co Armagh. The road was chosen deliberately, since it was one of the few leading into Co Monaghan that had was not blocked by the British army or overlooked from watchtowers.
There, they daubed slogans on the small Garda station which was shut overnight. Nearby "Ulster has Awakened" graffiti was painted on the walls of a former Church of Ireland national school and a pub. A slogan was painted too on the wall of the Garda station.
A Garda car arrived and two gardaí who got out to investigate were kicked to the ground and beaten with sticks. Another Garda car arrived from Monaghan with three detectives, who fired a number of shots into the air, dispersing the crowd, who returned across the Border.
Northern Ireland Office civil servants, in a report which was released decades later, said Mr Robinson “appears to have lingered behind deliberately”.
He was arrested and brought to Monaghan where he was held in custody for 32 hours. He refused all meals offered by the Garda, preferring the “wholesome Ulster food” supplied by his wife, Iris.
He was granted bail and later appeared in court in Drogheda, where he pleaded guilty to unlawful assembly and was fined IR£17,500.
This fine was later paid, earning Robinson the nickname – based on the then Irish currency – “Peter the punt”. He resigned as DUP deputy leader after Clontibret, but was later reinstated.
The DUP leader,
, said little, partly because he was out of the country at the time. Speaking shortly before his death, he said that the Clontibret invasion “shouldn’t have been done”. Asked if he believed that Mr Robinson had been making a leadership bid, he replied: “Everybody has a right to decide for themselves what their answer to that is.”