1943: The Battle of Kursk begins. It features the largest tank engagement in history. In purely military terms, it’s the most decisive battle of the European war. After Kursk, the defeat of Nazi Germany is certain.

Following their catastrophic defeat at Stalingrad five months earlier, the Germans lacked the strength to attack along the entire Eastern Front. The high command chose to focus on a salient near Kursk in Russia, near the Ukraine. There was an opportunity there to encircle and destroy a dozen Soviet armies. Following the elimination of that pocket, the Germans planned to strike northward at Moscow.

The operation, about which even Hitler expressed misgivings, was given the code name Zitadelle, or Citadel.

The Germans prepared deliberately for this attack, committing nearly a million men, 2,700 tanks and 2,000 aircraft. They would be facing a Soviet force of 1.3 million, backed by 3,600 tanks, 2,400 planes and more than 20,000 artillery pieces.

The battle that unfolded around Kursk was the apogee of tank warfare. The Soviets were equipped with probably the war’s most consistently efficient tank, the T-34, which had given the Germans a nasty shock early in the eastern campaign.

The Germans also possessed some excellent tanks (Panzer in German) — on paper at least — particularly the Panther, which had been designed specifically to take on the T-34. The heavy Tiger I also fought at Kursk, although the bulk of the German armor was composed of up-gunned Panzer IIIs and IVs.

The decisive engagement was fought at Prokhorovka on July 12, with German and Soviet tanks blasting away at each other from point-blank range. Although the Soviets suffered considerably heavier losses, overall German strength was ebbing fast.

With the Allied invasion of Sicily on July 11 and a new Soviet offensive beginning in the north, Hitler called off Zitadelle on July 13.

Kursk was where the operational initiative on the Eastern Front passed to the Red Army. No longer able to dictate the course of the war to an enemy that was only growing in strength, and with its own dwindling forces being siphoned off to meet threats in other theaters, Germany’s fate was sealed.

Source: Various

Photo: Soldiers with a Tiger I of the SS-Panzergrenadier-Division Das Reich advance through the southern Voronezh front at the Battle of Kursk. (German Federal Archives)

This article first appeared on Wired.com July 5, 2007.