German Pz.Kpfw. III, along with the IV, played an active part in the early stages of WWII as their mainstrength tanks
However when they encountered the Russian KV and T-34 tanks on the Eastern Front, the weakness of the Pz.Kpfw.III was revealed and the balance of power tipped in favor of the Russians
It was used for self-propelled guns till the end of the war