Act of Union

Ireland was a colony of the English from the 12th century. From the late middle ages it was a kingdom, under the same monarch as England, but a separate country. In law and in practice, the Irish government was usually subordinate to the English government.

Henry VIII rejected Rome and put the Church in England under his personal control. This church was to become more protestant, particularly under Elizabeth I. He had repeatedly attempted to subdue the island and turn it protestant, but Ireland's population remained mainly Roman Catholic. The conflict between Catholicism and Protestantism played a large part in 17th century with several wars in England and Ireland: civil wars, colonial wars, and at least one war.

In 1801 The United Kingdom of Great Britain and Ireland was formed as a political union. This was the end of the Kingdom of Ireland but not the conflict between Ireland and England.