The Northern-Irish conflict dates back to not only one, but probably several historical incidents.
In 1170, Henry 2 of England attemted to attatch Ireland to his kingdom. He did not succeed, but established control in a small area outside Dublin. For the remaining Irish clans, England now became their major enemy and threat, against their customs and way of life.
By the end of Queen Elisabeth’s reign, military conquests had established control in most parts of Ireland, with the exception of the northern province of Ulster. The Ulster clans had succeeded in creating an effective alliance against Queen Elisabeth’s armies, but was eventually defeated and brought under English rule. English colonists settled in these areas and by 1703 less then 5 per cent of the land of Ulster belonged to Catholics Irish. The native people of Ulster remained in the conquered areas, but were gradually expelled from the land that they used to own. The result of the settling of Ulster was the introduction of a foreign community, which spoke a different language, represented another culture and way of life. In addition, most of the newcomers were Protestants, while the native Irish were Catholic. This probably added a new dimension to the conflict.