The Panzer IV, which had a larger turret ring, was redesigned to mount the long-barrelled 7.5 cm KwK 40 gun and became the main German tank instead.

At the time, German (non-light) tanks were expected to carry out one of two primary tasks when assisting infantry in breakthroughs, exploiting gaps in the enemy lines where opposition had been removed, moving through and attacking the enemy's unprotected lines of communication and the rear areas.

[2] On January 11, 1934, following specifications laid down by Heinz Guderian, the Army Weapons Department drew up plans for a medium tank with a maximum weight of 24,000 kg (53,000 lb) and a top speed of 35 km/h (22 mph).

[3] It was intended as the main tank of the German Panzer divisions, capable of engaging and destroying opposing tank forces, and was to be paired with the Panzer IV, which was to fulfill the second use: dealing with anti-tank guns and infantry strong points, such as machine-gun nests, firing high-explosive shells at such soft targets.

Such supportive tanks designed to operate with friendly infantry against the enemy generally were heavier and carried more armour.

[6] A distinct feature of the Panzer III, influenced by the British Vickers Medium Mark I tank (1924), was the three-man turret.

As a result, production of self-propelled anti-tank guns (Panzerjaeger), as well as the up-gunning of the Panzer IV was initiated.

N, was created with a 75-millimetre (2.95 in) KwK 37 L/24 cannon, the same short-barreled low-velocity gun used for the initial models of the Panzer IV and designed for anti-infantry and close-support work.

However, the infantry at the time were being equipped with the 37-millimetre (1.46 in) PaK 36, and it was thought that, in the interest of standardization, the tanks should carry the same armament.

As a compromise, the turret ring was made large enough to accommodate a 50-millimetre (1.97 in) gun should a future upgrade be required.

[17] [18] [19] The Panzer III was used in the German campaigns in Poland, in France, in the Soviet Union, and in North Africa.

Many were still in combat service against Western Allied forces in 1944-1945: at Anzio in Italy,[b] in Normandy,[c] in Operation Market Garden in the Netherlands and in East Prussia against the Red Army.

[22] In both the Polish and French campaigns, the Panzer III formed a small part of the German armoured forces.

Aside from use in Europe, the Panzer III also saw service in North Africa with Erwin Rommel's renowned Afrika Korps from early 1941.

In particular, the 75mm hull-mounted gun of the Lee/Grant tank could easily destroy a Panzer III far beyond the latter's own effective firing range, as did the similarly equipped M4 Sherman, which first saw combat with British forces in North Africa in October 1942.

[citation needed] Around the time of the beginning of Operation Barbarossa in the summer of 1941, the Panzer III was, numerically, the most important German tank on the frontline.

[citation needed] However, the Panzer IIIs were significantly outclassed by the more advanced Soviet T-34 medium and KV series of heavy tanks, the former of which was gradually encountered in greater numbers by the German forces as the invasion progressed.

[24] Against the KV class of heavy breakthrough tanks, the Panzer III was a significant threat if it was armed with special high-velocity tungsten-tipped armour-piercing (AP) rounds.

L version began the use of spaced armour sideskirts and screens (known as Schürzen in German) around the turret and on the vulnerable hull-sides.

The Panzer III's strong, reliable and durable chassis was the basis for the turretless Sturmgeschütz III assault gun/tank destroyer, one of the most successful self-propelled guns of the war, as well as being the single most-produced German armoured fighting vehicle design of World War II.

[4] By the end of the war in 1945, the Panzer III saw almost no frontline use, and many of them had been returned to the few remaining armaments/tank factories for conversion into ammunition carriers or recovery vehicles.

A few other variants of the Panzer III were also experimented on and produced by German industries towards the last phases of the war, but few were mass-produced or even saw action against the encroaching enemy forces of the Americans, British and Soviets.

Ms, with Hitler hoping the country, militarily strengthened by Nazi Germany, could possibly threaten the Soviet Union from its southern border (in any case, neutral Turkey did not participate in any form of aggression towards the USSR or the Western Allies, and eventually declared war on Nazi Germany nearing the end of WWII instead, perhaps from Allied pressure).

The Soviets decided to upgun these captured German vehicles and two resulting designs were produced: the SG-122 self-propelled howitzer and the SU-76i assault gun.

The former was not well-designed and was only built in very small numbers, with most not seeing combat action at all, while the latter was regarded as a better option of a Panzer III-based assault vehicle with a larger 75mm main gun.

Purportedly this was for reverse engineering purposes, since Japan put more emphasis on the development of new military aircraft and naval technology and had been dependent on European influence in designing new tanks.