At their crawling stage, motor vehicles were instruments supporting men in the First World War. When it came to the Second World War, machine and man began to operate in coordination. Still, in doctrinal terms, the question how the infantry will serve in a mechanised war remained ambiguous for a long time. Until the first real armoured infantry fighting vehicle BMP-1 appeared.
The ancestors of mechanised infantry were the German “Panzergrenadier” (mechanised infantry) units dating back to the Second World War. Soldiers belonging to this class could support panzers, without interrupting the pace of the operation, by engaging the enemy from within semi-tracked SdKfz 251 armoured vehicles. Although Panzergrenadiers did not have to disembark from their vehicles, they nevertheless fired against the enemy by leaning out of the open-topped roof. Thus they could not benefit fully from the advantages of armoured protection. The Americans did not directly include semi-tracked armoured vehicles during fighting to transport soldiers to the battlefield. The question of how to use mechanised infantry effectively, remained an issue throughout the Second World War.
German General Fridolin Rudolf Theodor von Senger und Etterlin, with his accumulation of experience during the Second World War, launched a new idea as Germany was authorised to rearm in 1955. Articulating the inefficiency of the “battle taxi” approach in the US doctrine, including transport of the infantry to the battlefield under armoured protection, the General argued in favour of developing a vehicle to accompany main battle tanks, featuring terrain capability and ability to withstand against light weapons and shrapnel.