Horthy's nationalist agenda reached its apogee in 1938 and 1940, when the Nazis rewarded Hungary's staunchly pro-Germany foreign policy in the First and Second Vienna Awards, respectively, peacefully restoring ethnic-Hungarian-majority areas lost after Trianon. In 1939, Hungary regained further territory from Czechoslovakia through force. Hungary formally joined the Axis Powers on 20 November 1940, and in 1941, participated in the invasion of Yugoslavia, gaining some of its former territories in the south.