By 1943, World War II had turned decisively in the Allies’ favor. At Stalingrad, the Russians destroyed the Wehrmacht’s largest field formation, the Sixth Army. In the Pacific, the Americans and their allies won a hard-fought victory over the Japanese at Guadalcanal. In North Africa, Allied forces trapped the German Afrika Korps and its Italian partners and forced them to surrender. And back in Russia, the Red Army won the decisive Battle of Kursk.

In the winter of 1942-43, riding the momentum of their triumph at Stalingrad, Soviet forces launched a series of operations across the southern sector of their enormous front. Most met with at least some success. But in March, Field Marshal Erich von Manstein mounted a surprise counteroffensive that drove the Red Army’s battle-weary forces back from Kharkov and Belgorod.

Elsewhere, however, victory at Voronezh allowed the Russians to break through quickly to Kursk, a major transportation hub in central Russia. The result was a bulge in the front known in the West as the Kursk salient and in Russian as the Kurskaya Duga, or Kursk Arc. It projected roughly 150 kilometers westward, measured about 200 kilometers across at its base, and had Kursk at its center. To the north, it was flanked by the German-held Orel salient, which was roughly the same size. To the south, the German line formed a right angle with Belgorod at its corner.

The broad outline of Germany’s plan for the summer campaign of 1943 practically drew itself. After a winter of brutal fighting, the Wehrmacht no longer had enough strength to attack in several directions at once. Kursk, however, offered the best possible target for one concentrated blow. Major highway and rail hubs to the north at Orel and to the south at Belgorod and Kharkov would ease the logistical burden. The attack would have to cover a relatively modest distance – about 100 kilometers from each direction. By comparison, the Germans had advanced as much as 500 kilometers during their drive on Stalingrad in the summer of 1942. Encircling the Soviet armies inside the salient would inflict losses so severe that, for the next several months – perhaps even for the rest of the war – the Russians would be reduced to simply holding the line.

The coming operation was code-named Citadel. German forces would strike along converging axes at the base of the Kursk salient, then surge into the rear of the Soviet armies deployed inside it.

At first, the Germans did not intend to wait long. They planned to launch the offensive in the spring of 1943. Then other considerations intervened. In their memoirs, German generals usually had an elegant way of assigning responsibility for controversial decisions to a dead Führer who could no longer answer back. In reality, however, the man who first called for postponing the attack at Kursk was Walter Model, commander of the German forces north of the salient.

That winter, Model had “suffered a victory” near the town of Rzhev. The Germans had repelled a Soviet offensive there, but their own losses were too heavy to replace quickly. Now Model, who was supposed to attack the Kursk Arc from the north, wanted more time to prepare and as many reinforcements as he could get. Some other generals argued that the operation should be canceled altogether. Yet the Germans had no alternative plan for the summer of 1943. Trying to hold the entire front through passive defense was a dead end. Sooner or later, the Russians would find a weak spot. In war, it is critical to impose your will on the enemy and make him fight where it suits you.

In the end, the plan was simply revised to accommodate Model’s demands. The delay also gave the Germans time to stockpile ammunition and equip their forces with the latest armored vehicles. The most famous were the heavy Tiger tank, the medium Panther, and the Ferdinand tank destroyer. But the new arsenal included several other models as well, including such exotic machines as the Borgward demolition carrier.

Reinforcements poured into two main strike groups. In the north, Model’s Ninth Army had a fairly straightforward plan: smash through the defenses at a single point with a dense mass of tanks, then drive directly on Kursk. In the south, Manstein devised something more elaborate. Here, the Wehrmacht would attack like a trident. SS panzer divisions advancing toward Kursk through Prokhorovka formed the center prong, but their success depended on two flanking formations. One German panzer corps would advance farther west through Oboyan, while another would creep forward to the east, bypassing Belgorod from that direction. Such a three-pronged breakthrough threatened to trap Soviet forces in a series of encirclements before the Germans even reached Kursk, rapidly collapsing the armies south of the city.

The Germans’ problem was that the Soviets had not been sitting still, meekly awaiting their fate. The plan was too obvious, and intelligence reports confirmed what Soviet commanders had already suspected. As early as April, Marshal Georgy Zhukov outlined the enemy’s most likely course of action. Zhukov was no crystal-ball prophet. All it took to arrive at the broad conclusion was a look at the map and a basic understanding of the enemy’s condition.

Curiously, the Russians received independent confirmation of the coming offensive from intelligence agents operating among their own allies. Kim Philby and John Cairncross of the famous Cambridge spy ring sent Moscow a German radio message intercepted by the British that contained the plan for the operation. Some Soviet commanders favored a preemptive strike. Zhukov and Chief of the General Staff Alexander Vasilevsky, however, decided it would be far wiser to absorb and extinguish the force of the German blow, since they already knew where it would fall.

The Red Army spent the remaining time building defenses around Kursk.

Surrendering the initiative to the enemy is normally extremely risky, but in this case the Russians had a reasonably good idea of where the attack would come. Soviet industry, now operating at full capacity, was supplying the troops with enormous quantities of weapons and materiel. There were also enough men under arms to create not only formidable defensive lines, but a safety cushion in the form of massive reserves.

The Steppe Front was deployed across the base of the salient to provide fresh forces and stabilize the situation if the main line collapsed. A common mistake in discussions of the defense of Kursk, however, is to assume that Soviet commanders cared only about digging trenches, laying mines, and taking other measures designed purely to hold their ground. The reality was far more complex.

While troops facing the German armored fists dug into the earth, Soviet armies were preparing offensives of their own near Orel, north of the Kursk Arc, and in the Donbass to the south. At the decisive moment, those attacks were supposed to force the Germans to abandon their own operations and start plugging holes elsewhere. The Soviet offensives were therefore inseparably linked to the defense of Kursk.

The Russians had to hold out until the Germans were fully committed and had burned through men, machines, supplies, and ammunition. Then the Red Army would strike on other sectors. The offensives near Orel and in the Donbass were expected to force the Germans to halt their attacks around Kursk, while the stubborn defense of the salient would wear them down so badly that they could not stop the new Soviet advances.

In early July, the agonizing wait came to an end.

Konstantin Rokossovsky commanded the front defending the approaches north of Kursk. He received his final warning from the Stavka on July 2. On the night of July 4-5, a clash erupted in no-man’s-land when Soviet scouts ran into a group of German combat engineers clearing lanes through the minefields. Several Germans were killed and one was captured. The prisoner quickly told his interrogators everything he knew. Acting on his account, Rokossovsky immediately ordered his artillery to begin “counterpreparation” – a preemptive strike against the enemy’s gun batteries. Shelling the German positions before the offensive sounded like a good idea, but Soviet intelligence was inaccurate this time, and the barrage inflicted little damage. The decision was, frankly, a failure. Even so, it was with artillery fire in the predawn gloom that one of the largest battles in world history began.

The Germans may have been expected, but their opening blow still carried tremendous weight. They also deployed technically sophisticated assault formations equipped with Tigers and the latest combat-engineering vehicles. Yet advanced equipment alone could not guarantee a breakthrough. On the first day, Model’s forces pierced the Soviet front in only one sector. To their credit, the Germans had conducted careful, effective reconnaissance and achieved their initial success precisely where they had already identified a weak point.

Even there, however, no easy breakthrough followed. The Wehrmacht ran into minefields of staggering size, covered by artillery and sniper fire. Soviet antitank positions were so well concealed that the Germans usually found them only when the Russians opened fire.

The Germans still had one breach, but Rokossovsky had several reserve rifle divisions and an entire tank army with which to plug it. The constant churn of attack and counterattack disrupted the Germans’ momentum. Even successful Wehrmacht assaults developed slowly, allowing Soviet reserves to arrive and block the advancing units.

After the meager gains of the first few days, Model shifted his main effort toward Ponyri, a station on the railroad running from Orel to Kursk. It was hardly a natural fortress, but after months of preparation the Russians had turned it into a small stronghold ringed, inevitably, by minefields. The backbone of the defense, however, was not the mines. Nearly 20 artillery and antitank regiments and brigades were positioned around the station.

It took the Germans a long time to fight their way toward Ponyri. The defenses there could not win the battle by themselves, but they bought time to determine where the enemy intended to break through and to move reserves into place. Before long, the Germans were concentrating forces wildly out of proportion to the importance of this tiny station and had become trapped in a crude frontal slugfest. As a final argument, they sent in two battalions of their newest equipment: Ferdinand and Brummbär self-propelled guns, both armed with heavy weapons and built to withstand intense fire. On paper, they were a formidable proposition. Heavy assault guns were supposed to blast a path for the infantry deep into the Soviet lines.

In practice, the same thing happened as on the first day. After penetrating a short distance, the Germans found only more minefields and a kill zone covered by a sea of artillery of every conceivable type. The mines forced their vehicles to stop, and stationary armor became prey for the guns. The Ferdinands and Brummbärs were certainly well protected, but shells rained down on them, while the infantry could not follow the armored vehicles because the men had no armor of their own. Deprived of support and stranded before the minefields, the Wehrmacht’s steel battering ram was predictably mauled.

Four artillery regiments fired on the two battalions. Attempting to cross the minefield was deadly even for the heavily armored Ferdinands: conventional mines were interspersed with improvised charges made from aerial bombs and heavy shells. Simply escaping the breach became a problem. The remnants of the German assault units managed to withdraw only by abandoning numerous disabled Ferdinands and several Brummbärs on the battlefield. Rokossovsky later made sure to display these hunting trophies to the press, and Soviet soldiers and officers happily posed for photographers among them. Including tanks and support vehicles, some 35 to 40 machines were left behind in a single field.

Something similar unfolded farther west near Olkhovatka, where German attempts to break through resembled a desperate effort to smash a brick wall with their foreheads. They had to batter not only rifle divisions, but an entire tank army fighting on the defensive. In one final effort, the German corps commander at the spearhead grouped all his tanks into a single division, reinforced it with a Tiger battalion, and tried to punch through a narrow sector with a 200-tank horde. The Germans had some reason for optimism: in the summer of 1943, Soviet armor was markedly inferior in quality.

The legacy of 1942 – when everything capable of moving and firing had been thrown into battle – still made itself felt. Soviet formations contained large numbers of light tanks, still being produced according to the principle of “more of them, for less money,” as well as obsolete Lend-Lease vehicles.

As at Ponyri, artillery became the bedrock of the Soviet defense. The fighting continued largely through inertia, shaving several thousand men a day from the German army while its offensive ground to a complete halt. Model also resisted committing all his forces at once. He expected a Soviet attack on Orel and wanted to retain at least some battleworthy reserves. He would not have to wait long.

South of Kursk, where General Nikolai Vatutin was in command, the situation was much worse. Manstein simply had considerably more forces than Model, and he committed them generously from the very beginning, holding nothing back in reserve. As in the north, the southern “trident” sprang into action on July 5.

The Red Army divided its formations into much smaller units than the Wehrmacht did. A Soviet army was roughly equivalent to a German corps – and was sometimes smaller – while a Red Army corps might be no larger than a second-tier German division. It is hardly surprising, then, that the defenses began to buckle when two German corps slammed into the Soviet Sixth Guards Army.

Even so, the Germans did not have an easy time of it. While the Nazis in the north stalled before the minefields, Manstein’s western prong ran into a colossal antitank ditch. The Russians had “improved” a long, deep, swampy ravine by packing it with explosives, creating an obstacle that held up large German forces. After finally struggling across, they were drawn into savage fighting. For the same reason, the Germans could not use their regiment of brand-new Panthers as a battering ram. They also made an uncharacteristic mistake by failing to provide the Panthers with enough infantry and combat engineers. The result was predictable: one mine explosion after another. The number of Panthers actually destroyed was not spectacular, but the number still fit for combat plunged dramatically and remained between 20 and 50 out of an original 200. Most of the tanks sat forlornly in repair depots.

Meanwhile, however, the SS Panzer Corps found a weak point and, in barely a day, smashed through a defensive line that had taken months to prepare. Here, the Germans not only achieved overwhelming numerical and technical superiority, but put it to effective use. Once again, it must be said that they had conducted painstaking, successful reconnaissance and knew where to strike. At the same time, the episode exposed the inescapable weakness of passive defense: the enemy decides where the main battle will be fought, and you may guess wrong about the location – as defenders usually do.

The front did not collapse west of the German breakthrough. As in the north, a tank army stabilized the situation. This time, the Germans ran into the tankers of General Mikhail Katukov. Facing an assault by hundreds of tanks, Katukov showered the advancing Germans with counterattacks, aided by reinforcements sent from the reserves. The left prong slowed. At the same time, Manstein’s right prong also became bogged down. The positions east of Belgorod along the Seversky Donets River were considered a secondary sector, but the Soviet defenders managed to slow the German tanks there, if not stop them altogether. Vatutin could therefore regard the course of the battle on his eastern and western flanks as more or less satisfactory.

The problem was that, at that very moment, the SS was grinding down the Soviet reserves in the center. The enormous, superbly equipped SS corps advanced like a battering ram, and regiments and brigades arriving from the rear shattered against it like glass. For the time being, the Soviets could not stop the SS.

The glass was half empty, but it was also half full. Every day of the offensive cost the Germans roughly 10% of the armored vehicles committed to the attack. Despite local defeats, Katukov’s tankers and the Soviet infantry had hobbled the German left prong. Even the elite Grossdeutschland Division lost most of its equipment. Soviet high command, however, had no clear picture of the enemy’s condition. More importantly, the SS corps – the knife aimed at the heart of the front – was still moving forward. The Stavka therefore made the quick decision to draw on its safety cushion: the forces of the Steppe Front. The Fifth Guards Tank Army was dispatched from there to meet the SS.

Meanwhile, the II SS Panzer Corps lunged far to the northeast and reached Prokhorovka Station, between the Psel and Seversky Donets rivers. The advance had not been easy.

Counterattacks immediately battered the SS flanks, but something still had to be done about the breakthrough itself – especially since the Germans had already captured the Fifth Guards Tank Army’s intended starting positions for its own counterattack. Units of the SS Leibstandarte Division that had reached Prokhorovka took up defensive positions and prepared to widen the breach toward the Psel. Then, on July 12, the Soviet reserves – the Fifth Guards Tank Army – came crashing down on them.

Unfortunately, the counterattack at Prokhorovka was very poorly prepared. The Fifth Guards Tank Army attacked straight from the march and received nowhere near enough artillery support, let alone air cover. In the rush, there was no time for proper reconnaissance, so the Soviet tankers went in almost blind. Worse still, the same haste meant that the Germans were not struck by an entire tank army advancing in a single formation, but by brigades arriving one after another.

It recalled the ill-fated Soviet counterattacks of the summer of 1941, only in an even worse form. Back then, at least, T-34s and KVs could exploit their powerful armor – by the standards of the time – and close with the enemy. Now the attackers were met by shells from heavily armored German tanks and self-propelled guns that Soviet fire could barely penetrate. Over the course of July 12, the Fifth Guards Tank Army suffered devastating losses while only marginally reducing the SS formations’ ability to continue their advance.

The Germans certainly suffered significant damage: 50 to 70 of their tanks were destroyed or disabled, compared with more than 300 Soviet vehicles. But even the Leibstandarte Division, which absorbed the main blow, remained combat-effective. Strange as it may sound, nothing especially disastrous happened to the Germans at Prokhorovka. In practical terms, the Soviets had merely reset the problem to where it had been before.

Yet the forces of Manstein’s right prong, which had been trying to reach Prokhorovka from the other side, were hobbled and failed to break through. The left prong was bogged down as well. The SS now stood alone deep inside the Soviet defenses, without help or support. And elsewhere, the front was beginning to split at the seams…

On July 12, as armored armies collided head-on at Prokhorovka, the Soviet Western and Bryansk fronts launched their offensive north of Kursk. Their primary objective was to break through toward Orel. The attack immediately succeeded in several sectors. Walter Model received the news almost with relief. From that point on, there was no longer any question of continuing the northern drive on Kursk.

A Soviet breakthrough toward Orel would carry the Russians directly into the rear of the German forces fighting around Kursk. Model’s immediate superior, Field Marshal Günther von Kluge, did not hesitate for a second. On the first day alone, he dispatched three panzer divisions, one infantry division, and several independent assault-gun brigades to counter the threat. The strike force north of Kursk was dismantled with astonishing speed, almost as though the Germans had been waiting for an excuse. Citadel’s northern pincer had been crossed out with a thick Iron Cross. Rokossovsky’s forces could finally catch their breath: they had held for exactly as long as required.

Orel, however, was not the Nazis’ only problem. On July 10, the Allies had begun landing in Sicily at the opposite end of Europe. That same day, German intelligence detected preparations for a major Soviet offensive in the Donbass, which would indeed begin on July 17. Nor was there much comfort to be found south of Kursk itself. The corps on either side of the SS had been hobbled and could offer no help. The SS corps had broken through and repelled the Soviet counterattacks, but it now sat amid a raging sea of Soviet troops. Continuing the advance offered uncertain benefits, while the Germans risked losing an entire series of battles elsewhere in the meantime. Manstein insisted that, with reinforcements and continued pressure by Model on Rokossovsky, his troops could have reached Kursk. In reality, his argument contained far too many “ifs.”

If Manstein received fresh divisions, if they managed to grind down the Soviet reserves, and if Model resumed his attack, Manstein promised that he could reach Kursk – which still would not have encircled the Soviet armies. Meanwhile, as he fought his way toward the city, the last rites could already be read over the German forces in the Donbass and around Orel. No wonder the Führer passed on that kind of good fortune. Army Group South halted its attacks, and German reserves scattered across the front to plug one gap after another. The Leibstandarte Division was sent to Italy and three more divisions to the Donbass. Operation Citadel had failed completely.

Paradoxically, the Germans were not stopped at the battle’s most famous site – the field at Prokhorovka. On the contrary, it was the only place where the Nazis had achieved success by July 12 and retained the ability to continue their advance. That fact in no way diminishes the courage of the men who counterattacked the SS and died in the armored melee. But the Wehrmacht was stopped primarily by skillful, well-timed operations across the entire front, not by what happened in a single sector.

The Russians had, so to speak, gone over to the offensive at the enemy’s expense. Now they had to make intelligent use of the situation.

Around Orel, the Russians attacked from three directions: east, northeast, and north. The eastern advance proceeded in fits and starts, but it created a crisis in the German defenses and forced the Wehrmacht to commit reserves. More importantly, those German efforts could do no more than contain it. Northwest of Orel, meanwhile, the situation was turning catastrophic for the Wehrmacht. Ivan Bagramyan’s Eleventh Guards Army quickly broke through the front, and Soviet tank corps poured into the breach. The Germans managed to slow the advance, but within days it became clear that Alexander Gorbatov’s Third Army, driving straight toward Orel from the east, and the Eleventh Guards Army approaching from the north threatened to collapse the German defenses throughout the Orel salient. With the Russians committing a tank army on each axis, the German position became critical.

Contrary to his usual stubbornness, Hitler quickly agreed with his generals that Orel had to be abandoned. The Germans took the breakthrough so seriously that the elite Grossdeutschland Panzer Division – 19,000 men, roughly equivalent to two Soviet tank or mechanized corps – marched around the entire Kursk salient and was transferred from south to north. The Germans managed to slow the Soviet offensive considerably. Soviet commanders would later assess their own performance with striking self-criticism, identifying serious flaws in the operation’s organization. Rokossovsky, who was pressing against the salient from the south at the same time, described it as “pushing” the enemy out rather than destroying him. Even so, it was an unmistakable victory: the Germans were forced to evacuate the Orel salient. The Wehrmacht did withdraw in good order to the fortified Hagen Line at the salient’s base, which the Red Army would have to breach in a separate operation.

Events farther south were even more dramatic.

Vatutin needed time to rebuild his strength and restore order to his front after Manstein’s ferocious offensive. The Russians filled that pause with an attack in the Donbass. Fyodor Tolbukhin’s Southern Front broke through the Wehrmacht defenses along the Mius River and began moving west. The Germans were determined not to surrender the Donbass, a major industrial region, and immediately sent several panzer divisions there. The Russians gave battle. Although the fighting near the village of Stepanovka is far less famous than Prokhorovka, the Germans suffered much heavier losses there, battling Soviet rifle and tank units in sun-drenched cornfields. They managed to push Tolbukhin’s strike force back to its starting positions, only to race straight back toward Belgorod and Kharkov without so much as a pause. The Soviet offensive there began on August 3. The Russians quickly captured Belgorod and drove a wedge into the German defenses north of Kharkov. As at Orel, the Germans tried to stabilize the situation by rapidly maneuvering their panzer divisions. The battle south of Kursk became chaotic, with both sides creating local encirclements and the situation shifting abruptly. On August 23, it culminated in the liberation of Kharkov and the formal end of the Battle of Kursk.

One of the greatest successes of the summer campaign was achieved by what was, on paper, the weakest Soviet force. Tolbukhin’s Southern Front had taken a beating in late July when it failed to break into the Donbass. It was the weakest of the fronts advancing west and had the fewest tanks. But now, with the Germans having withdrawn nearly all their mobile reserves toward Orel and Kharkov, Tolbukhin saw his opportunity. The Russians attacked again almost immediately after losing the first battle on the Mius – and won the second in brilliant fashion. Tolbukhin once more smashed through the front, but this time Manstein could not bury him under panzer divisions. The Russians turned sharply south and pinned a group of several German divisions against the Sea of Azov. The Germans fought their way out of encirclement, abandoning their heavy weapons. Having cleared this mass of enemies from his flank, the Soviet commander wheeled north again and emerged behind the German forces in the Donbass. To escape encirclement, they began a rapid, disorderly retreat from the industrial towns of the steppe. The Donbass, almost impregnable only a short time before, was liberated with remarkable speed and an almost matter-of-fact ease. Hitler raged, but there was nothing he could do. By the end of the first week of September, the Wehrmacht had been driven from the Donbass.

In the wake of these battles, Manstein had to retreat all the way to the Dnieper River. The whole of Army Group South rapidly fell back west toward a line considered strong enough to stop the Red Army’s further advance. The Russians paid dearly for their success. The Wehrmacht remained a highly effective fighting force, and Soviet losses in the battles were approximately twice as high as the Germans’. But the Wehrmacht had lost the strategic initiative. Never again would the Nazis be the active side across the front as a whole. The Russians had liberated a territory the size of a small European country. The German line had lost its stability, and for the next several months the Wehrmacht would be forced to retreat westward, constantly scrambling to patch the holes in its formations.

Kursk is often held up as a model defensive operation. But it is essential to remember that the battle was never simply a matter of sitting behind fixed defenses. The successful defense of Kursk went far beyond digging trenches, laying minefields, and preparing kill zones. It required constant offensive action within the defense, and above all, the preparation of an entire cascade of offensives beyond the Kursk Arc itself. By the time the battle around Kursk reached its climax on the SS corps’ sector, Soviet attacks in other directions had rendered the SS effort pointless – even if it succeeded.

On the Eastern Front, Kursk marked the Wehrmacht’s final strategic offensive. Hard and bloody battles still lay ahead, but no one seriously doubted any longer who would win the war. The German high command still hoped to lock the conflict in a clinch and fight its way to an overall stalemate by clinging to the Dnieper line. Within three months, Berlin would be stripped of that illusion as well.