Dublin Metropolitan Police

The DMP was established by an Act of Parliament in 1836, following the model of Sir Robert Peel's London Metropolitan Police, which had been founded in 1829. It replaced the earlier Dublin Police, which had been in operation since 1786, and was initially under the control of the Dublin Castle administration. The force was unarmed, a distinctive feature that set it apart from the armed RIC, and its officers were known for their distinctive dark blue uniforms and top hats. The first commissioners were appointed from the British military and police tradition, and the force quickly gained a reputation for efficiency and discipline.

The DMP was responsible for policing the city of Dublin, including its docks and public buildings, and for maintaining public order during political demonstrations and events. It operated a detective branch, a mounted unit, and a river police, and it was known for its meticulous record-keeping and its use of photography in criminal identification. The force also played a role in social services, such as administering the city's night refuge for the homeless. During the Irish War of Independence (1919–1921), the DMP was largely unarmed and often targeted by the IRA, leading to resignations and a decline in effectiveness.

After the establishment of the Irish Free State in 1922, the DMP was initially retained, but in 1925 it was amalgamated with the Garda Síochána, the new national police force. The merger was part of a broader consolidation of state institutions, and it ended the DMP's separate identity. Many former DMP officers transferred to the Garda, and some of its records and traditions were absorbed. The DMP's legacy includes its pioneering use of photography and its role in the development of modern policing in Ireland, as well as its distinctive unarmed style, which influenced the Garda's own unarmed policy.

One lesser-known aspect is the DMP's 'G Division', the detective unit that worked closely with British intelligence during the War of Independence, and whose members were often assassinated by the IRA. Another is the force's role in the 1913 Dublin Lockout, where it was criticized for its handling of labor protests. The DMP also had a women's police branch, established in 1915, one of the earliest in the British Isles. Additionally, the DMP's band was renowned and performed at public events, and its training manual, the 'DMP Code', was considered a model of police regulation. The force's archives, now held in the National Archives of Ireland, are a valuable resource for historians.

Garda Síochána

The national police service of the Republic of Ireland, established in 1922.

Royal Irish Constabulary

The armed police force of Ireland outside Dublin, disbanded in 1922.

Dublin Castle

The seat of British administration in Ireland until 1922.