Causes
The roots of the 1641 rebellion lay in the failure of the English State in Ireland to assimilate the native Irish elite in the wake of the Elizabethan conquest and plantation of the country. The pre-Elizabethan Irish population is usually divided into the "Old (or Gaelic) Irish", and the Old English, or descendants of medieval Norman settlers. These groups were historically antagonistic, with English settled areas such as the Pale around Dublin, south Wexford, and other walled towns being fortified against the rural Gaelic clans.
However, by the seventeenth century, the cultural divide between these groups, especially at elite social levels, was declining. Many English lords not only spoke the Irish language, but extensively patronised Irish poetry and music, and were described as Hiberniores Hibernis ipsis (more Irish than the Irish themselves). Intermarriage was also common. Moreover, in the wake of the Elizabethan conquest, the native population became defined by their shared religion, Roman Catholicism, in distinction to the new Church of England and Church of Scotland of settlers, and the officially Protestant (Church of Ireland) English administration in Ireland. During the decades between the end of the Elizabethan wars of re-conquest in 1603 and the outbreak of rebellion in 1641, the political position of the wealthier landed Irish Catholics was increasingly threatened by the English government of Ireland.
Read more about this topic: Irish Rebellion Of 1641