The Bureau of Military History was established in January 1947 by Oscar Traynor TD, Minister for Defence and former Brigade Commandant of the Dublin Brigade after the death of Richard McKee.

The objective of the Bureau was 'to assemble and co-ordinate material to form the basis for the compilation of the history of the movement for Independence from the formation of the Irish Volunteers on 25th November 1913, to the 11th July 1921.' (Report of the Director, 1957).

Over the following eleven years 1773 witness statements, 334 sets of contemporary documents (which include items such as pamphlets, photographs, letters, dispatches, drawings and sketches, posters, legal documents, newspaper clippings, commemorative publications and various ephemera),  42 individual photograph collections, 210 photographs of action sites during Easter Week taken subsequently by the Air Corps, 12 voice recordings, and a collection of press cuttings were assembled by the Bureau. These were contributed by a variety of people who were largely either participants or witnesses to the events covered by the terms of the Bureau of Military History.

The establishment of the Bureau gave individuals involved a chance to record their own stories. Members of groups such as the Irish Volunteers and subsequently the IRA, Cumann na mBan, the IRB, Sinn Féin, the Irish Citizen Army, relatives of deceased individuals and people not associated with any specific organisation were sought out to provide as broad a range as possible to the collection. The Bureau of Military History collection is open to the public.

The dedicated website for the Bureau of Military History is available for the public to view following the official launch, which took place on Tuesday 7th August 2012 by Mr. Jimmy Deenihan, T.D., Minister for Arts, Heritage and the Gaeltacht.