The War File: Battlefield: Campaign In The Balkans (2002) DVD
 
In August 1943, the Romanians--no doubt prompted by merciless Allied bombing--changed sides. Thereafter, events moved swiftly: the Russians soon captured the vital Ploesti oil fields, a huge loss to the German war effort, and within days the Soviets captured Bucharest. A nervous Bulgaria sued for peace with the Allies, but the Russians pushed on into Sofia. Despite German delaying tactics, Hungary fell next. In Yugoslavia, the Germans held grimly on to Belgrade until October. The bloody mop-up fighting was left to the Soviets and lasted until the end of the war.