Besides land reform, Gladstone was also committed to disestablishing - breaking the link between church and state - the Anglican Church of Ireland. Catholics, who considerably outnumbered Protestants in Ireland, had long resented this.
In 1865 Gladstone informed Parliament of his intentions, a statement which led directly to his defeat in his Oxford constituency at the ensuing general election.
He was not out of the Commons for long and returned as an MP for another constituency a month later. In March 1868 Gladstone took advantage of a motion on the state of Ireland to declare that the connection between the Irish church and state ought to be severed.
Benjamin Disraeli, the Conservative Prime Minister, was opposed, but on 3 April Gladstone won a majority of 56 on a motion that the House should go into committee in order to consider disestablishment.
Gladstone's resolutions were subsequently carried with even larger majorities. Disraeli called an election in November 1868 on the church question and Gladstone's Liberal Party was rewarded with a majority of 112.
“My mission is to pacify Ireland” declared Gladstone on becoming Prime Minister again, and for the next two years he concentrated on the Church Bill, which became the Church Act in 1869. Conservative opposition was strong, but it passed its third reading with a good majority on 31 May.
Opposition in the House of Lords was even stronger but it also passed the Bill.
As of 1 January 1871 the Church of Ireland was no longer the state church.