| Second Congress of Berlin (Treaty of Berlin)|
| 13 June 1922|
|Effective|| 14 June 1922|
|Signatories|| Albania, Austria, Czech-Slovak Delegation, Germany, Hungarian Delegation, Italy, Croat Delegation, Poland, Serbia, Banat Delegation, Romania, Turkey, Soviet Russia|
|Language|| English, Czech, French, German, Italian, Magyar, Polish, Portuguese, Russian, Serbo-Croat, Turkish, Albanian.|
The Second Congress of Berlin was convened in the wake of Kaiser Karl I's death in April 1922, at first to manage the unstable political situation in Austria-Hungary. Participants included Germany, Great Britain, Soviet Russia, Austria Hungary including "Austria-Hungary", "Hungary", "Czechoslovakia", "Yugoslavia", "Banat" or more technically the Imperial and Royal government, and the parliamentary assemblies in Budapest, Prague, Zagreb, and Temoschwar.
Poland , the Ottoman Empire, Ukraine, Baltic State, and Bulgaria initially sent official observers. The conference was expanded to settle the borders of Albania, (at the expense of Serbia, which was concluded as separate agreements) affirm the grand ducal status of the Baltic State, (and tacitly Lithuania as a kingdom) and to restart and reroute the Berlin to Baghdad Railway .
Great Britain, Romania and Russia as former enemies of Germany also participated. Russia was still in civil war and was ostensibly represented by the Bolshevik government, which had signed the peace treaty with Germany in 1918.
France was not invited, and Italy declined to participate in the beginning of the conference. It resulted in the break up Austria-Hungary and the formal recognition of an independent Hungary, Czechoslovakia, Yugoslavia, and Banat. It left unsettled the Crown of St Stephen, and the political structure of Yugoslavia, which became nominally a "kingdom" in personal union with Austria. Germany had made vague guarantees to the Czech national army during the Great War for an independent Czech state, but its presence resulted in a de facto Czechoslovak republic.
Hungary would continue with a regent until 1961, Otto would reclaim the Crown of St. Stephen in 1962 as to Hungary only. The borders of Albania, the Austrian Empire, Hungary, Czechoslovakia, Yugoslavia, and Banat were confirmed. Additional treaties would be signed between the states regulating that arrangement, and the titles of the Austrian Emperor. The Yugoslav states would be in personal union with the Austrian Emperor, but as independent states. They would be considered part of the "Austrian Empire" assuming a relationship similar, although looser to that of Canada in the British empire. The Yugoslav constitution limited the authority of the "Emperor/King" to largely ceremonial functions only. E.g., new titles of nobility could not be granted without Parliamentary consent; with exception of the Maria-Theresa order and the Golden Fleece. The military swore an oath to "The People of Yugoslavia" and to "obey the lawful orders of the Kaiser."
Additional protocols "re-affirmed" the neutrality of the Congo basin, as had been agreed to in 1885, but not adhered to during the Great War.