The Romans didn't invade Ireland.
They are said to have had plans to do so but didn't go ahead.
They probably had trade alliances and social contacts with Ireland. It is very unlikely that some Irish mercenaries did not fight with the Roman army.
Given the close proximity between Britain and Ireland the Romans and Irish probably had a good knowledge of each other. Possibly the Roman administrators and military personell had reasons for not pushing their influences into Ireland on a scale parallelled elsewhere.
The culture, laws and traditions in Ireland remained untouched by Roman influences as did their religion. Ireland remained in the 'Iron Age' until around 450-500AD and their Druids remained influential until the advent of established Christianty in Ireland.
No the Celts living there scared them off the idea, same with Scotland but instead of the Celts they had the Pict's to deal with
St. Patrick was a Roman citizen that Irish slavers had kidnapped. So thats activity between the Irish and Romans.
There is no evidence to sugest tht the Romans inavded Ireland.
Unlike the rest of the British Isles ( apart from the North of Scotland), Ireland has no archaelogical remains ascribed to the Roman period, nor any evidence for Roamn influence.
It is more likely that Roman Traders visited Ireland and exchanged the resouces Ireland had available for export. Intermarriage betwee the native Irish and the peoples of the Roman Empire probably took place, if only on a small scale.
A burial in Ireland revealed the body of a women dressed in clothes which were described as in the Roman style. It is thought that she may have been the wife of an indiginous Irish man or the wife of a Roman trader who had settled in Ireland.
Artefacts rom the Roman period were found deposited at Newgrange the pre-historic monument in Meath. These may have been imported from Britain or elsewhere.
First of all there was an invasion
but there was only one legion ie 100 men this was due to confusion of Ireland's size it was possible it was mixed up with the isle of man then ireland was named hibernia which I think means land of wet and cold which was an excuse not to invade which makes no sense as they tried to invade scotland an even colder wetter region also there was evidence of trade.
And just to throw this in
several irish kingdoms invaded britain after the fall of the roman empire,they were destroyed in wales northern england and Plymouth but completely conquered scotland and f.y.I Scottish in the Scottish language meant irish up to the 17th/18th century.
Rome conquered everything they could and Irish scholars try to hide the fact that there was a roman fort near dublin YET to be excavated. And 200 years of roman coins are found all over ireland. So it's obvious Rome conquered ireland. Anyone they traded with was conquered shortly afterward. Ireland is NO exception....