Armoured divisions

The development of the tank near the end of World War I prompted some nations to experiment with forming them into division-size units. Many did this the same way as they did cavalry, by merely replacing infantry with tank units and giving motorization to the support units. This proved unwieldy in combat, as the units had many tanks but few infantry units. Instead, a more balanced approach of balancing the number of tank, infantry, and artillery units within the division took place.

By the end of World War II, in most cases armoured division referred to divisions with significant tank battalions and motorization for its infantry, artillery, and support units. Infantry division referred to divisions with a majority of infantry units.