The Odessa Front was founded in December 1942 as the war on the Eastern Front began to push westwards, and the Soviet lines were spread too thin. They needed an army group to operate on the Black Sea coastline, as the Crimea Fronts were already engaged in the Siege of Sevastopol. The Odessa Front was made up of 1,000,000 Red Army troops from two armies created especially for the army group. Konstantin Serebryannikov was put in command of the army group, who operated in the southern Ukraine and along the border with Romania. The Odessa Front fought in the South Ukraine Theater against the Romanians, Germans, and rarely, the Bulgarians, who did not fight much. Serebryannikov's army group fought in the Reni-Kiliya Offensive in April 1944, the Jassy-Kishniev Offensive in June, and the Bucharest Offensive in August-September 1944. Their last campaign was assisting Yugoslav partisans and Romanian clean sweeps in the Balkans (after Rumania became Romania once more), remaining there until May 20, when Private Gunther Keller was killed, the last German casualty.