A Lithuanian Guard of Honor stands triumphantly beside the Three Crosses monument (Lithuanian: Trys kryžiai) in Vilnius after the city is returned to Lithuania. Following WWI, both Poland and Lithuania contested ownership of the city. On 9 October 1920, the Polish Army surreptitiously seized Vilnius during an operation known as Żeligowski’s Mutiny. However, the secret protocols of the Soviet-German Molotov-Ribbentrop Pact of 1939 had partitioned Lithuania and Poland into German and Soviet spheres of interest prior to the outbreak of war. On 19 September 1939, Vilnius was seized by the Soviet Union (which had invaded Poland on 17 September 1939). The Soviet Union and Lithuania concluded a mutual assistance treaty and on 28 October 1939 Vilnius was given back to Lithuania. This was part of a larger plan by the Soviets, as unwitting Lithuania would be invaded, occupied and annexed by the Soviet Union on 21 July 1940. The original Three Crosses memorial would be blown up by the Soviet authorities in May 1950 to prevent the structure from being viewed by citizens with any nationalist reverence. Vilnius, Lithuania. October 1939.