Excerpts from Books and Wikipedia
"The period begins with the defeat of the Catholic Jacobites in the Williamite War in Ireland in 1691 and ends with the Act of Union, which formally annexed Ireland to the United Kingdom in 1801." [Wikipedia]
"The Protestant Ascendancy, known simply as the Ascendancy, was the political, economic, and social domination of Ireland between the 17th century and the early 20th century by a minority of landowners, Protestant clergy, and members of the professions, all members of the Established Church (Church of Ireland or the Church of England). The Ascendancy excluded from politics and the elite other groups, most numerous among them Roman Catholics but also members of the Presbyterian and other Protestant denominations, along with non-Christians such as Jews. Until the Reform Acts (1832–1928) even the majority of Irish Protestants were effectively excluded from the Ascendancy, being too poor to vote. In general, the privileges of the Ascendancy were resented by Irish Catholics, who made up the majority of the population." [Wikipedia]