The Dáil Courts were the judicial branch of government of the short-lived Irish Republic, during the Irish War of Independence. They were formally established by a decree of the First Dáil Éireann on 29 June 1920, replacing more limited Arbitration Courts that had been authorised a year earlier. The Dáil Courts were an integral part of the Irish Republic’s policy of undermining British rule in Ireland.
The precursor of the Dáil Court system was a forum for arbitration commonly known as the 'Sinn Féin Court'. In 1904, Arthur Griffith had reiterated the idea of National Arbitration Courts in every county:
....not less important to the nation than a National Civil Service are National Courts of Law. Hungary understood this and established Arbitration Courts, which superseded the courts which Austria sought to impose upon her. Ireland, before O'Connell retreated from the proposal of erecting a de facto Irish Parliament in Dublin, had established such courts. I say it to my countrymen, as The Nation said to them in 1843, "You have it in your power to resume popular courts and fix laws, and it is your duty to do so. If you resort in any of your disputes to any but your own judges, you injure yourselves and commit treason to your country."
At a Ministry meeting of 23 June 1919, it was decided to set up a committee on Arbitration Courts. Unlike the rules that then regulated who could become a Justice of the Peace, women were expressly eligible to become judges in the new courts. The general idea of Parish and District Courts on the lines of those then operating in South County Mayo, County Galway and West County Clare was approved. The Parish Courts were usually arbitrated by local Irish Republican Army, Catholic clergy, or Sinn Féin figures who had authority in the area. In appearance they were less formal than the British civil courts and its officers did not wear regalia associated with the legal profession of the time such as gowns and wigs. They filled a vacuum created by the conflict, and sought to persuade people who were inclined to fear the IRA's revolutionary nature that an independent Ireland would not set aside personal and property rights. During the war, the courts gradually extended their influence across most of the country, usurping the British law courts as the British government lost its authority in the eyes of the majority.