Hmm. It isn't much of a religious conflict, but more of a territorial one. It was a conflict between the Protestants/Unionists and the Catholics/Republican in the Northern Ireland equation. Many of the Protestants were originally the decendants of the settlers who emigrated from England, with the encouragement of the English government who was planning to "plant a loyal British garrison community to establish control in the face of periodic Irish uprisings which at times threatened English security by linking up with England's traditional Catholic enemies, France and Spain." So you see, the Catholics and Protestants were kinda enemies from the start. The Protestants refused to admit themselves as Irish but British, and preferred Northern Ireland to remain part of UK. However, the Catholics preferred that Northern Ireland were to be part of the Republic of Ireland.
