In July 1941, the Kingdom of Hungary, a member of the Tripartite Pact, took part in Operation Barbarossa, in alliance with Nazi Germany. Hungarian forces fought shoulder to shoulder with the Wehrmacht and advanced through the Ukrainian SSR deep into Russia, all the way to Stalingrad. However, by the end of 1942 the Soviet Red Army began pushing back the Wehrmacht through a series of offensives that preceded the Red Army's encroachment upon Hungarian territory in 1943–44. In September 1944 Soviet forces crossed into Hungary, launching the Budapest Offensive. As the Hungarian army ignored the armistice with the USSR signed by the government of Miklós Horthy on 15 October 1944, the Soviets fought their way further westward against the Hungarian troops and their German allies capturing the capital on 13 February 1945. Operations continued until early April 1945, when the last German forces and their remaining loyal Hungarian troops were routed out of the country.