Ion Antonescu governed Romania from 1940 until 1944. Antonescu aligned Romania with the Axis powers in November 1940, and became one of Nazi Germany's closest allies. Romania joined in the German invasion of the Soviet Union in 1941. It also implemented harsh anti-Jewish policies against Jews in Romania. While Antonescu ultimately refused to hand Jews over to the Germans, Romanian forces brutally killed hundreds of thousands of Jews, mainly residents of Bessarabia, Bukovina, and the western Ukraine. As the war turned against the Axis and Soviet forces entered Romania in 1944, Antonescu was arrested and turned over to the Soviet Union as a war criminal. Soviet authorities returned Antonescu to Romania in 1946 to stand trial. A tribunal found him guilty of war crimes. He was executed on June 1, 1946.