$  In September 1939 Germans had two types of tanks that could be classified as medium tanks: PzKpfw III$
$and PzKpfw IV.  Their armour was up to 30 mm thick. Panzer III was armed with 37 mm gun. Heavier Panzer IV$
$was armed with a short-barreled 75 mm gun.  At the time Wehrmacht had at its disposal only a small number$
$of these tanks.  Because of this, these tanks were grouped in mixed third companies of tank battalions.$
$  Thick armour of these tanks made them a difficult target for Polish anti-tank crews. Both types were in$
$active service until the end of the war.  Their armour was gradually increased and their guns were improved.$
$  At the very end of war Panzer III's use was very limited, but Panzer IV, together with Panthers and$
$Tigers formed the mainstay of Panzerwaffe. Used in early versions of PzKpfw IV short barrel was of no use$
$against heavy French or Russian tanks, but in 1939 that disadvantage was almost meaningless.$
