The Irish Republican Brotherhood (IRB) was a small, secret, revolutionary body (known as the Fenian movement in the 1850s and 60s), committed to the use of force to establish an independent Irish republic. After organising an abortive rising in March 1867, it suffered deep internal divisions over leadership and strategy whether it was best to strike at England in Ireland or in Canada. The issue was resolved after a series of failed interventions in Canada in 1866, 67 and 71. The IRBs reorganisation was begun after the release from prison in 1871 of two of its most effective leaders - Jeremiah O`Donovan Rossa and John Devoy. Its constitution was amended in 1873; it was thereafter to be governed by a partially elected, eleven-man Supreme Council, representative of its seven British and Irish electoral divisions; members swore to regard this Council as the Government of the Irish Republic.
With no immediate prospect of effective revolutionary action, the IRB leaders agreed to co-operate with the Irish Parliamentary Party, then under Parnells dynamic leadership, in mobilising tenant agitation for land reform (known as the new departure, 1879-82). They hoped to weaken British authority and to generate increased popular support for the republican cause. Meanwhile, during the 1880s, the Brotherhood organised a dynamite campaign in English cities.
Riven by continuing internal squabbles, the IRB was unable to exploit the weakness and divisions in the constitutional movement following Parnells divorce scandal, 1890-91. It was eventually rejuvenated, between 1910-12. The key figure in purging its aging leadership was Tom Clarke, himself a veteran Fenian. Supported by a new generation of young, committed members he succeeded in bringing a new sense of purpose and vitality to the organisation, so that it was able to exploit any favourable opportunities for insurrection when they arose. In 1913, a group within the IRB encouraged the formation of the Irish Volunteer Force (IVF). After the force split (September 1914), these elements (including Clarke) successfully infiltrated the dissident IVF rump which had rejected Redmonds appeal to enlist in the British Army. They hoped to use these Volunteers in an insurrection, which they considered opportune, given the outbreak of war in Europe. The Easter Rising was planned by the seven-man IRB Military Council - a body set up on Clarkes initiative (May 1915), whose activities were concealed even from the IRB Supreme Council.
Many republicans blamed the secretiveness of the IRB for the confusion surrounding the Rising and for its failure. After World War One, they argued that it had served its purpose and was no longer needed, and that the Dail government - established January 1919 - should control and direct the Irish Republican Army (IRA). The revival of the IRB after 1916 and its considerable influence within both the Dail and the IRA during the Anglo- Irish war (1919-21), was chiefly because Michael Collins, the IRB President and Minister of Finance, still valued it. He considered that it had a vital role to play, especially in gathering intelligence and he resisted the efforts of other Sinn Féin politicians to gain control of the IRAs military campaign. The IRB divided over the Treaty (December 1921) - most rank and file members opposed it - and the organisation did not survive the impact of the Irish Civil War and formation of the Irish Free State.