When German tank divisions were organized in 1935, the Germans naturally started development plan for vehicles carrying infantrymen to support tank forces. In 1938, the German Army decided to develop an armoured personnel carrier on the basis of 3-ton half track (HL-KL-9p) mentioned above. Hanomag Hannoversch Machinenbau (AG) in Hannover was ordered to develop the running gear and Bussing-NAG in Berlin was to develop the superstructure to be armoured. Design work was hastened on the model of existing armoured cars and a prototype was completed at the end of 1938. The Germans tested the prototype in the Kumahsdorf Proving Ground and accepted it for mass production. Thus was born the Armoured Personnel Carrier Hanomag Sd.Kfz. 251/1 which, we may safely say, was a synonym for the German mechanized corps that showed activity in all battlefields throughout the war. The type A (the first production type) employed a Maybach HL-42, 6-cylinder 4,171 cc engine of 100 hp. The transmission permitted four speed forward and one backward. The armour thickness was 14.5mm at the front, 8mm on the sides and 6mm at the bottom. The maximum speed was 55 km/h. This vehicle could carry 12 fully armed soldiers in addition to tow crew-members. Production was immediately started by Hanomag and Goliath. In 1942, Adler-Werke AG, Auto-Union and Skoda of Pilsen (now in Czechoslovakia) joined them.

In the Polish Campaign, a limited number of Sd.Kfz.251's first saw battle on 9th September, 1939. General Heinz Guderian in command of the 3rd Tank Division was in a Sd.Kfz.251/3 which was equipped as a commander's vehicle. Making full use of its mobility, he moved around the battlefield and became famous for his undaunted command. The Hanomag Armoured Personnel Carriers of Type A and Type B were produced until the French Campaign of 1940. The two types were the same in performance and construction but slightly different only in appearance. They were distinguished from each other by soldiers, peep windows on the body sides. The type A had a number of such windows, while the Type B had none except for the driver's ones.
In the Polish Campaign where Hanomag personnel carriers first saw action and the French Campaign which was started soon after that, the advantages of infantry mechanized by the personnel carriers were not made the most of from a tactical point of views. This is not merely because the personnel carriers used were limited in number but because they were often used by machine-gun platoons and engineer companies and for towing infantry guns rather than for carrying infantrymen. It was not until the Russian Campaign which started in 1941 that fully mechanized infantry exercised its terrible power in united action with tanks.

The Type C was put into production at the end of 1940. The type C was improved in body construction and employed 100% welding process in place of the former combination process of bolting and welding. Three shielded light machine guns of model 34 were mounted as the standard equipment. The armour was equal in thickness to that of the previous types. In 1941, the Type was officially designated "Armoured Personnel Carrier (SPW)". Until the Type D appeared in 1943, the Type C played an important part in support of German tank forces in the gallant days of blitzkrieg against Russia from the Operation Barbarossa to the Battle of Stalingrad. Especially in the German Summer Offensive of 1942 which the Russian leaders referred to as "Gloomy Summer of 1942", German tank divisions used a great number of Type C's and drove the Russians back to the Volga.

The Armoured Personnel Carrier developed into the further improved Type D and came to have a wide variety of equipment and armament. In all, 22 variations ranging from the Sd.Kfz. 251/1 equipped only with shielded machine guns to the Sd.Kfz.251/22 armed with a 75mm AT gun of 48 length calibre were manufactured. It is reported that the total production reached about 16,000 by the end of 1944.
World War II was a war of mechanized power, that is to say, a war of systemized power. It must not be overlooked that the part - although not the leading part - which the German armoured personnel carriers played in and the influence they exerted on this total war were very great and also that most of personnel carriers used during the war were of half-track type.