Seen as a splinter group of the Irish Republican Army, it was formed in County Tyrone by Liam Kelly and Phil O'Donnell in 1953. Kelly had been expelled from the IRA in October 1951 for carrying out an unauthorised raid in Derry, and took some of his colleagues with him into the new organisation.. The new group carried out armed robberies. In 1954, a political wing, Fianna Uladh, was formed. Kelly was later elected to the Seanad in 1954, due mainly to the efforts of Seán MacBride,with the group maintaining close links to Clann na Poblachta. Unusually for republican groups at the time Saor Uladh recognised the legitimacy of the Constitution of Ireland and the Dáil Éireann.
Saor Uladh was involved in 1955 in an attack on the RUC barracks in Rosslea, County Fermanagh in which a volunteer was killed,  on the 11 November 1956 Saor Uladh and members of a Dublin IRA splinter group destroyed six-customs posts along the border in bomb attacks  and in May 1957 the group blew up the canal lock in Newry with gelignite that they had stolen.  The group was armed by contact Kelly had in the United States of America, from they received not only guns and explosives but even anti-tank weapons. Despite this potentially vast arsenal the group confined itself to attacks on barracks and the bombing of bridges and customs posts during its period of actvity.
Saor Uladh were closely associated with the revisionist, leftist, Irish republicanism of the Clann na Poblachta party - then in government - though no formal link was ever established or admitted and their central political demand was the replacement of the Parliament of Northern Ireland with a nine county Dail Uladh to determine the future of the "North of Ireland".
Their military campaign saw the destruction of several customs posts and raids on police installations. Saor Uladh had its main presence in County Tyrone and in this area the IRA was forced to tolerate the group's existence due to the popularity of Kelly.  At the beginning of the Border Campaign the group was subsumed back into the IRA. In May 1957, the group blew up the locks on Newry Canal.  Twelve of the group's members were interned at the Curragh Camp in 1957, where they were ostracised by the IRA internees.
During their brief existence two members of the organisation were killed.