The Panzerkampfwagen III, commonly known as the Panzer III, was a medium tank developed in the 1930s by Germany, and was used extensively in World War II. It was intended to fight other armoured fighting vehicles and serve alongside and support the similar Panzer IV, which was originally designed for infantry support. However, as the Germans faced the formidable T-34, more powerful anti-tank guns were needed, and since the Panzer IV had more development potential with a larger turret ring, it was redesigned to mount the long-barrelled 7.5 cm KwK 40 gun. The Panzer III effectively swapped roles with the Panzer IV, as from 1942 the last version of Panzer III mounted the 7.5 cm KwK 37 L/24 that was better suited for infantry support. Production of the Panzer III ceased in 1943. Nevertheless, the Panzer III's capable chassis provided hulls for the Sturmgeschütz III assault gun until the end of the war.

The Panzer III was intended as the primary battle tank of the German forces. However, when it initially met the KV-1 heavy tanks and T-34 medium tanks it proved to be inferior in both armour and gun power. To meet the growing need to counter these tanks, the Panzer III was up-gunned with a longer, more powerful 50-millimetre gun and received more armour but still was at disadvantage compared with the Soviet tank designs. As a result, production of self-propelled anti-tank guns, as well as the up-gunning of the Panzer IV was initiated.


A distinct feature of the Panzer III, influenced by the British Vickers Medium Mark I tank (1924), was the three-man turret. This meant that the commander was not distracted with another role in the tank (e.g. as gunner or loader) and could fully concentrate on maintaining awareness of the situation and directing the tank. Most tanks of the time did not have this capability, providing the Panzer III with a combat advantage versus such tanks. For example, the French Somua S-35's turret was manned only by the commander, and the Soviet T-34 originally had a two-man turret crew. Unlike the Panzer IV, the Panzer III had no turret basket, merely a foot rest platform for the gunner.


In 1942, the final version of the Panzer III, the Ausf. 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. For defensive purposes, the Ausf. N was equipped with rounds of HEAT ammunition that could penetrate 70 to 100 millimetres (2.76 to 3.94 in) of armour depending on the round's variant, but these were strictly used for self-defence.