The IRSP was formed in 1974 when it broke off from Official Sinn Fein/OIRA due to major ideological differences. The IRSP felt that the Official movement was becoming overly reformist with regaurds Imperialism in Ireland. Upon its birth the IRSP was subjugated to a bloody war with the OIRA in an attempt by the Official movement to wipe out the new party. During this war the INLA was created in an attempt to defend the party membership and wage a National Liberation war with the elements of Imperialism occupying Ireland. The INLA waged a war against British Imperialism in Ireland for about 25 years and called a cease-fire after the Good Friday Agreement but the IRSP still vehemently opposes Imperialism and native capitalism in Ireland only recognising as of now a War of National Liberation is unsustainable in the current political context of Ireland. The IRSM is predominantly a Northern Based movement with Offices in Strabane, Belfast and Derry. Many renowned figures have been in the Irish Republican Socialist Movement either as IRSP members or INLA Volunteers or both. These include the party founder Seamus Costello, Bernadette Mc Aliskey, Ta Power, Ronnie Bunting, Tony Gregory, Gino Gallagher, Mickey Devine, Kevin Lynch and Patsy O'Hara.
