The legal basis for the operations of the Commissioners of Irish Lights dates back to an Act passed by the Irish Parliament sitting in Dublin in 1786.

This act of Grattan's Parliament created a body entitled: "The Corporation for preserving and improving the Port of Dublin". As indicated by its title, its functions were the maintenance and preservation of the Port of Dublin. Until the year 1810 it had no jurisdiction over, or connection with lighthouses or allied matters. However, in that year, subsequent to the abolition of the Irish Parliament, an Act was passed by the British Parliament, entitled Lighthouses (Ireland) Act 1810, which transferred to the Corporation created by the Irish Act of 1786, all powers, duties and functions relating to the control of Lighthouses around the coast of Ireland, though the title and constitution of the Corporation remained unchanged.

The Merchant Shipping Act of 1854 conferred on the Corporation a new and separate title -'The Port of Dublin Corporation'. The effect was, in essence, to divide the existing Corporation into two distinct corporate bodies with separate functions.

The Corporation for Preserving and Improving the Port of Dublin, the original body, was to maintain and improve the Port of Dublin while the new body - The Port of Dublin Corporation had transferred to it all functions, powers and duties in relation to lighthouses, beacons etc., around the coast of Ireland.

Severance

In 1867, the severance begun by the Merchant Shipping Act of 1854 was completed. The new Act separated the Port of Dublin Corporation from the Corporation for the Preserving and Improving the Port of Dublin. In doing so it changed the name of the former to the Commissioners of Irish Lights and the latter to the Dublin Port and Docks Board. However, through the provisions of the 1867 Act, the legislative provisions in regard to the composition, method of election, power to appoint and remove staff and to make rules, regulations, bye-laws, etc., of the Commissioners of Irish Lights, continued to be those provided for in the original Irish Act of Parliament of 1786.

With the advent of Irish independence, it became necessary for the new State to legitimise its functions. Though provided for in the 1922 Constitution of the Irish Free State, it was not until 1935 that things were finally regularised when adaptations necessary to enable the Commissioners of Irish Lights to be fully operative in the Irish Free State were made by an Order of the Executive Council, entitled: Irish Lights Commissioners Adaptation Order, 1935. Subject to these adaptations, the relevant provisions of the Act of 1786 remain in force to date. In a very real sense, the governance of the Commissioners of Irish Lights remains a remarkable testimony to the far sightedness and legislative ability of an Irish Parliament sitting in Dublin in 1786.