RTFA: http://en.wikipedia.org/wiki/Battle_of_Kursk

The Battle of Kursk refers to German and Soviet operations on the Eastern Front of World War II in the vicinity of the city of Kursk in July and August 1943. It remains both the largest series of armored clashes, including the Battle of Prokhorovka, and the most costly single day of aerial warfare to date. It was the last strategic blitzkrieg offensive the Germans were able to execute in the east. The resulting decisive Soviet victory gave the Red Army the strategic initiative, which it kept for the remainder of the war.

The Kursk salient (also known as the Kursk bulge) was created in the aftermath of the German defeat at the Battle of Stalingrad. The Germans hoped to shorten their lines by eliminating the salient, with pincers breaking through its northern and southern flanks to achieve yet another great encirclement of Red Army forces. However, the Soviets had good intelligence of Hitler’s intentions. This and repeated German delays to wait for new weapons, including the Panther tank, gave the Red Army time to construct elaborate, layered defenses and position large reserve forces for a strategic counterattack.[3]
” Although often thought of as a tank battle, Kursk as a whole arguably demonstrated the triumph of artillery, infantry and engineers over armour. The Soviet plan was to soak up the German assault in a colossal web of defensive positions, and only then launch their armoured counter-attack. It was also an important air battle, in which the balance now shifted in the favour of the Soviets. “

I stumbled across this World War II battle while doing some research. This little discussed event is one of the largest warfare battles in the history of humans.

“they had collected 200 of the new Panther tanks (only 40 were available at the beginning of the operation due to technical problems with the new type), 90 Elefant Panzerjägers and all 79 flyable Henschel Hs 129 ground attack aircraft[21], as well as 270 Tigers, late model Panzer Mark-IVs and even a number of captured T-34s.[22] In total they assembled some 3,000 tanks and assault guns, 2,110 aircraft[23][nb 1] and 900,000 men. It formed one of the greatest concentrations of German fighting power ever put together. Even so, Hitler expressed doubts about its adequacy.”