Béla Kun was a Hungarian communist revolutionary and politician who governed the Hungarian Soviet Republic in 1919. After attending Franz Joseph University at Kolozsvár, Kun worked as a journalist up until the First World War. He served in the Austro-Hungarian Army and was captured by the Imperial Russian Army in 1916, after which he was sent to a prisoner-of-war camp in the Urals. Kun embraced communist ideas during his time in Russia, and in 1918 he co-founded a Hungarian arm of the Russian Communist Party in Moscow. He befriended Vladimir Lenin and fought for the Bolsheviks in the Russian Civil War.

The armistice of Belgrade was an agreement on the termination of World War I hostilities between the Triple Entente and the Kingdom of Hungary concluded in Belgrade on 13 November 1918. It was largely negotiated by General Louis Franchet d'Espèrey, as the commanding officer of the Allied Army of the Orient, and Hungarian Prime Minister Mihály Károlyi, on 7 November. It was signed by General Paul Prosper Henrys and vojvoda Živojin Mišić, as representatives of the Allies, and by the former Hungarian Minister of War, Béla Linder.