The total number of troops involved on the Eastern Front with the Romanian Third Army and the Romanian Fourth Army was second only to that of Nazi Germany itself. The Romanian Army had a total of 686,258 men under arms in the summer of 1941 and a total of 1,224,691 men in the summer of 1944. The number of Romanian troops sent to fight in the Soviet Union exceeded that of all of Germany's other allies combined. A "Country Study" by the U.S. Federal Research Division of the Library of Congress attributes this to a "morbid competition with Hungary to curry Hitler's favor... [in hope of]... regaining northern Transylvania." Bessarabia and the Northern Bukovina were now fully re-incorporated into the Romanian state after they had been occupied by the USSR a year earlier. As a substitute for Northern Transylvania, which had been given to Hungary following the Second Vienna Award, Hitler persuaded Antonescu in August 1941 to also take control of the Transnistria territory between the Dniester and the Southern Bug, which would also include Odessa after its eventual fall in October 1941. Although the Romanian administration set up a civil government, the Transnistria Governorate, the Romanian state had not yet formally incorporated Transnistria into its administrative framework by the time it was retaken by Soviet troops in early 1944. Romanian armies advanced far into the Soviet Union during 1941 and 1942 before being involved in the disaster at the Battle of Stalingrad in the winter of 1942–43. Petre Dumitrescu, one of Romania's most important generals, was commander of the Third Army at Stalingrad. In November 1942, the German Sixth Army was briefly put at Dumitrescu's disposal during a German attempt to relieve the Third Army following the devastating Soviet Operation Uranus. Prior to the Soviet counteroffensive at Stalingrad, the Antonescu government considered a war with Hungary over Transylvania an inevitability after the expected victory over the Soviet Union. Although it was an ally of Germany, Romania's turning to the Allied side in August 1944 was rewarded by returning Northern Transylvania, which had been granted to Hungary in 1940 after the Second Vienna Award. Throughout the Antonescu years, Romania supplied Nazi Germany and the Axis armies with oil, grain, and industrial products. Also, numerous train stations in the country, such as Gara de Nord in Bucharest, served as transit points for troops departing for the Eastern Front.