The Republic of Ireland established a formal relationship with Northern Ireland in the 1930s that continues to this day.
Republic of Ireland . The state had no formal relations with Northern Ireland for most of the twentieth century , but during the 1980s and 1990s the British and Irish governments worked with the Northern Ireland parties towards a resolution to `` the Troubles '' . Since the signing of the Good Friday Agreement in 1998 , the Irish government and Northern Ireland Executive have co-operated on a number of policy areas under the North-South Ministerial Council created by the Agreement .