Soviet occupation of Bessarabia and Northern Bukovina
The Soviet occupation of Bessarabia and Northern Bukovina took place from June 28 to July 4, 1940, as a result of the ultimatum by the Soviet Union to Romania on June 26, 1940, that threatened the use of force. Bessarabia had been part of the Kingdom of Romania since the time of the Russian Civil War and Bukovina since the dissolution of Austria-Hungary, and Hertza was a district of the Romanian Old Kingdom. Those regions, with a total area of and a population of 3,776,309 inhabitants, were incorporated into the Soviet Union. On October 26, 1940, six Romanian islands on the Chilia branch of the Danube, with an area of , were also occupied by the Soviet Army.