The Lord Justice of Ireland was an ancient senior position in the governance of Ireland, held by a number of important personages, such as the Earl of Kildare.
In the later centuries of British rule the Lords Justices were three office-holders in the Kingdom of Ireland who in the absence of the Lord Lieutenant of Ireland fulfilled the social and political duties of the Viceroy as head of the Irish executive.
The office-holders were usually:
Among their duties was to welcome the incoming Lord Lieutenant when he arrived in state in the port of Dublin, having travelled from Great Britain to take up his post.
The decision in 1765 of the government of Great Britain to require the viceroy to be a full-time resident in Ireland, rather than just pay visits during sessions of parliament, removed the need for the Lords Justices, while the abolition of the Parliament of Ireland in 1800 meant that there was no longer a speaker of the House of Commons to serve as a Lord Justice.
After the Easter Rising of 1916, the British Government withdrew the Lord Lieutenant of Ireland, Lord Wimborne, and the Chief Secretary for Ireland, Augustine Birrell, back to Britain. Both men had been responsible for the civil government of Ireland and under these unusual circumstances the British Government appointed Lord Justices on 11 July to carry out their functions; however, as martial law was then in place, General Sir John Maxwell was actually the individual largely responsible for governing Ireland. The Lord Justices were Lord Castletown, Sir David Harrel, Richard Cherry (the Lord Chief Justice of Ireland), James Owen Wylie and Jonathan Pim (both Judges of the Supreme Court of Judicature of Ireland). The Lord Justices were not in place for long as a new Chief Secretary, Henry Duke, was appointed on 31 July and Lord Wimborne was re-appointed as Lord Lieutenant in the following days.