20th century: A Century of Change

The RDS Library remained at Leinster House until June 1922 when General Michael Collins of the Provisional Government of the Irish Free State decided that the RDS Lecture Theatre was the most suitable venue in which the new Irish Parliament (the Dáil) could meet. This was to be a temporary measure lasting no longer than eight months. When it became apparent that no other venue could be found in Dublin, the Government informed the RDS that it wished to occupy Leinster House on a more permanent basis. The RDS vacated Leinster House in 1924 and moved its headquarters to Ballsbridge. New accomodation was built in Ballsbridge by the RDS with the assistance of a grant of £68,000 from the Irish Government.

The National Library building was finally completed in 1926, two years after the NLI passed into the hands of the Irish Free State under the direction of the Department of Education. Throughout the 20th century the NLI continued to build and develop its national collections taking as their basis the material acquired in 1877 from the RDS Library and the Joly Bequest and assisted by the Legal Deposit act of 1927. By the early 1940s the NLI had been given responsibilty for the Chief Herald of Ireland's Office. The 1980s and 1990s saw the expansion of the Library's buildings on Kildare Street and the opening of the National Photographic Archive in Temple Bar, designed to house the NLI's expanding photographic collections.