Excerpts from Books and Wikipedia
"On January 1, 1801, the Act of Union established the 'United Kingdom of Great Britain and Ireland.' The Irish parliament in Dublin disappeared, and Ireland elected 100 Members of Parliament to the House of Commons, while two Irish Lord Spiritual and 28 Lords Temporal sat in the House of Lords.… Pitt had promised to include Catholic emancipation--the right of Catholics to sit in Parliament and hold public office--in the act, but King George III would not entertain the idea. . . . Nothing seemed to change as a result of the act, with the Viceroy in Dublin Castle and the Protestants still dominating Ireland. The Catholics were left feeling betrayed, and the national and religious divide was strengthened. Trouble lay ahead." [1001 Days]