The Republic of Montenegro was a constituent federated state of the Federal Republic of Yugoslavia and then Serbia and Montenegro between 1992 and 2006. The declaration of independence of Montenegro in 2006 ended the ex-Yugoslav state. After the collapse of the Socialist Federal Republic of Yugoslavia (SFRY), the remaining republics of Montenegro and Serbia agreed to the formation of the Federal Republic of Yugoslavia (FRY) which officially abandoned communism and endorsed liberal institutions. Montenegro was a constituent republic of the FRY and its successor state until June 2006 when Montenegro declared independence from Serbia and Montenegro following the 2006 Montenegrin independence referendum.