On 1 January 1943, with German Sixth Army about to be destroyed in the Stalingrad pocket, the Stavka (Soviet High Command) launched Operation Don, a strategic offensive conducted by the Red Army’s Southern, Southwestern, and Trans-Caucasus Fronts aimed at demolishing German defenses in the southern Soviet Union and decisively turning the war’s tide. Critical to this ambitious operation was the mission assigned to the Trans-Caucasus Front—to isolate and destroy German Army Group A in the northern Caucasus region in cooperation with the Southern Front. Operation Don’s Left Wing is the first detailed study of this crucial but virtually overlooked Soviet military operation. Because of the priority given to the assault on German Sixth Army at Stalingrad, the Red Army Southwestern, Southern, and Trans-Caucasus Fronts were compelled to execute their missions with scant resources—inadequate logistical support, personnel replacements, and reinforcing equipment. Based on newly released Red Army archival operational documents, David M. Glantz constructs a clear, comprehensive account of how, despite such constraints, the Trans-Caucasus Front nonetheless pursued and severely damaged German First Panzer Army—although it failed to encircle and destroy the panzer army as hoped. These documents include candid daily orders and reports, periodic situation maps, a full array of ever-changing operational plans, and strength and casualty reports prepared by Soviet formations and units throughout the offensive. With unprecedented access to these documents, Glantz delves into previously forbidden topics such as unit strengths and losses and the foibles and attitudes of commanders at every level. Following Glantz’s Operation Don’s Main Attack, this documentary study expands our understanding of a pivotal operation in the Soviet triumph over Nazi Germany and a decisive moment in the history of World War II on the Eastern Front.