From Wikipedia, a brief history of the fast-paced and complex events that was World War II:
"The 'Axis powers' formally took the name after the Tripartite Pact was signed by Germany, Italy, and Japan on 27 September 1940, in Berlin. The pact was subsequently joined by Hungary (20 November 1940), Romania (23 November 1940), Slovakia (24 November 1940), and Bulgaria (1 March 1941)."
"The pre-dominantly ethnic German commanders of the army generally favored troops of German extraction, but ethnic Hungarian troops were also seen as being reliable and were widely used on the front lines, especially on the Russian front and Italian front."
"In September 1944, Soviet forces crossed the Hungarian border. On 15 October, Horthy announced that Hungary had signed an armistice with the Soviet Union. The Hungarian army ignored the armistice, fighting desperately to keep the Soviets out."
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