The state was created as the Irish Free State in 1922 as a result of the Anglo-Irish Treaty. It had the status of Dominion until 1937 when a new constitution was adopted, in which the state was named "Ireland" and effectively became a republic, with an elected non-executive president as head of state. It was officially declared a republic in 1949, following the Republic of Ireland Act 1948. Ireland became a member of the United Nations in December 1955. It joined the European Communities (EC), the predecessor of the European Union, in 1973. 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.