The Irish Republican Police (IRP) was the police force of the 1919–1922 Irish Republic and was administered by the Department for Home Affairs of that government.
The IRP was founded between April and June 1920 under the authority of Dáil Éireann. It was initiated by Richard Mulcahy the IRA Chief of Staff, and Cathal Brugha, Minister for Defence. It was handed over to the Minister for Home Affairs Arthur Griffith and later to his successor Austin Stack. Simon Donnelly, an IRA Staff Officer at GHQ, was transferred to the Department of Home Affairs as Chief of Police. At this time there were only six full-time Republican Police in Dublin city. Donnelly immediately instructed that a paid full-time policeman be appointed to each of the seventy-two IRA Brigade areas. They were chosen by the Brigades, and most though not all were IRA volunteers. The purpose of the IRP was to provide security for the Republican Courts, to enforce their judgements, to put into effect the Decrees of the Dáil and to maintain general order. It also occupied itself with such mundane matters as enforcing licensing regulations, dealing with theft and maintaining street patrols. From a propaganda perspective, as with all the institutions of the Irish Republic, it sought to put into effect secession from the United Kingdom. More specifically, the existence of the IRP was considered an important component in the campaign to undermine the authority of the Royal Irish Constabulary.
Irish republicanism (Irish: Poblachtánachas Éireannach) is an ideology based on the belief that all of Ireland should be an independent republic. The development of nationalist and democratic sentiment throughout Europe in the eighteenth and nineteenth centuries was reflected in Ireland in the emergence of republicanism, in opposition to British rule. This followed hundreds of years of British conquest and Irish resistance through rebellion. Discrimination against Catholics and Non-comformists, attempts by the British administration to suppress Irish culture, and the belief that Ireland was economically disadvantaged as a result of the Act of Union were among the specific factors leading to such opposition.