Much of the confusion regarding Irish history of the 1640's stems from the interrelationship between political, religious and cultural forces that motivated the people of the era. It is very difficult for historians to parse the elements of these forces, which had a varying degree of effect on individuals and events. It was during this period that the radicalization of religion and politics that had taken place in England swept over Ireland. The response to this radicalization was demonstrated by the Ulster rising of Phelim O'Neil that ultimately led to the formation of the Confederation of Kilkenny. At the same time, the general breakdown of civil authority caused by the inability of the crown to maintain order led to increasing religious, political and cultural conflict in Ireland, as the Catholics and Protestants sought to settle old enmities. In large measure, the turmoil was aggravated by the lack of a moderate and universally recognized central authority due to the weak rule of Charles I and the focus of Parliament on its quarrel with the crown.
At the beginning of the decade, Protestants in Ireland viewed Catholics with a mixture of contempt and fear, while the Catholics sought ways to establish their ascendancy over the Protestants. Beckett argues that the Catholic rising in Ulster in 1641 was largely prompted by this mutual hatred that had been simmering since the Ulster Plantation commenced during the reign of James I. He further contends that rising was initiated as the result of miscalculation of the level of support for the rising among the Old English, or descendents of early English settlers who lived in the region around Dublin known as the Pale. While the Old English initially supported the rising, they eventually shifted their position and sought a truce with the king in 1643.