• Montenegro is recognized under international treaties. 

  • Following World War I, Montenegro becomes part of the Kingdom of Serbs, Croats, and Slovenes. 

  • The Kingdom of Serbs, Croats, and Slovenes is renamed the Kingdom of Yugoslavia.

  • Montenegro becomes one of the republics in the new Socialist Federal Republic of Yugoslavia. The other republics include Serbia, Slovenia, Macedonia, Croatia, and Bosnia

  • Following the collapse of communism, Montenegro joins Serbia to form the Republic of Yugoslavia. 

  • The Dayton Accord brings an end to the Bosnian War and the UN sanctions on Yugoslavia. 

  • The Federal Republic of Yugoslavia joins the United Nations.

  • Leaders of Yugoslavia, Montenegro, and Serbia sign a European Union mediated accord establishing a new Union of Serbia and Montenegro, which replaces Yugoslavia. 

  • Montenegro adopts the euro as its national currency.

  • Montenegro votes in referendum, by a margin of 55.5%, to separate from Serbia. Serbia responds by declaring itself the independent sovereign successor to the Union of Serbia and Montenegro.

  • Montenegro officially applies to become a member of the European Union.

  • Montenegro citizens are granted visa-free travel within the European Union's Schengen Zone.

  • Montenegro joins NATO.

Sources:

BBC News open_in_new
Britannica open_in_new