Panther is the common name of a medium tank fielded by Nazi Germany in World War II that served from mid-1943 to the end of the European war in 1945. It was intended as a counter to the T-34, and to replace the Panzer III and Panzer IV; while never replacing the latter, it served alongside it as well as the heavier Tiger tanks until the end of the war. The Panther's excellent combination of firepower, mobility, and protection served as a benchmark for other nations' late war and immediate post-war tank designs, and it is frequently regarded as one of the best tank designs of World War II.
The development of the Panther resulted from the Wehrmacht's unpleasant surprise encounter with the Soviet T-34 during Operation Barbarossa, the German invasion of Russia in June 1941. During the first weeks of Barbarossa, the Panzertruppen repeatedly encountered the T-34/76 medium tank. Although in short supply, the T-34 made a quick and lasting impression on the German armored forces through its combination of speed and mobility, rugged reliability, sloped armor protection and firepower. As a result of several encounters with the T-34, especially the mauling sustained by the 4th panzer division at Mtsensk on 4 October 1941, Colonel General Heinz Guderian, leading Panzergruppe 2 in Army Group Centre, requested the establishment of a commission of enquiry into the relative strengths of the tank armies on the Eastern Front.