With the Fall of France in May / June of 1940, the Germans found themselves with a healthy stock of former French military goods including tanks. One type in the lot was the pre-war FCM-36, a light infantry tank produced in just 100 examples from 1938 to 1939. Some 37 of these were captured by the Germans and redesignated as "Panzerkampfwagen 737 FCM(f)" and used for a short while. In 1943, ten of the stock were modified as tank destroyers in the "Marder I" guise. In 1942, a batch of twelve were earmarked for modification as Self-Propelled Howitzers to become the "10.5cm leFH 16 (Sf) auf Geschutzwagen FCM(f)".
The conversion to an SPH was relatively straightforward as the basic underlying workings of the combat tank remained. Surplus 10.5cm leFH 16 series howitzers were then installed over the middle-rear of the hull, leading to deletion of the original turret. Around this emplacement was set a thin, open-air armored workspace for the gunnery crew. The driver maintained his position inside the hull while the gunnery crew totaled three operators. The radio fit was the Fu.Spr.Ger set. Length of the vehicle was 4.6 meters and width was 2.14 meters. The height of the French tank was now 2.15 meters. Drive power was the original French Ricardo-Berliet 4-cylinder diesel unit of 91 horsepower. Road speeds reached 17 miles per hour and range was out to 124 miles.
The leFH 16 howitzer was afforded 50 projectiles stowed about the vehicle - mainly along the inside walls of the new superstructure. For secondary armament, the 7.92mm MG34 machine gun was fitted. This could prove critical in defending the vehicle from infantry attack or low-flying aircraft. 2,000 rounds of 7.92mm ammunition were carried for it. Beyond this, any personal weapons carried by the crew came into play for defense.
Conversions of eight to twelve FCM-36 series tanks (sources vary) was had in the latter part of 1942. Complications were experienced due to the relatively modern nature of the French tank design coupled with the ages-old leFH 16 howitzers (having debuted in World War 1). Such delays worked against the program and may represent why fewer than a dozen were ever completed. They ended up assigned to German mechanized artillery formations where they proved their worth as compact, economical solutions - if only for a short time - as all were out of service by 1944.