The "half-track" saw its peak combat usage during the fighting of World War 2 (1939-1945) and many designs centered around a basic concept were thrown into the mix before the end. By installing a continuous track-and-wheel arrangement under the rear of a truck-like body, and retaining the roadwheels (complete with steering functionality) at the front, a new vehicle was born that held the cross-country capabilities of a tank with the steering control of a traditional truck. This allowed for useful war loads to be carried alongside the advancing mechanized force and many such vehicles were armed and armored for other battlefield roles beyond cargo-hauling.
One of the more numerous half-tracks to see service with the Army of France heading into the war became the UNIC "P.107" - a development of Citroen based on a standing Kegresse patent. The vehicle was another entry in the long-running series of French half-tracks dating back to the 1920s with the P.107 model of 1934 representing its strongest offering to date - aiding its popularity - and this model succeeded the earlier P.17 series. Following Citroen's bankruptcy, UNIC was able to gain a production license from new parent Michelin.
The P.107 would be produced in two distinct versions during its long operational service life - the first became a dedicated artillery tractor used for the towing of French Army light Anti-Tank (AT) guns and indirect-fire artillery pieces. A soft top was standard issue to protect the crew (numbering five-to-seven) from the elements but did little to protect them against even minor battlefield dangers. Projectiles and other pertinent mission equipment for the guns could be carried in onboard storage spaces making the P.107 an all-in-one solution. The alternate variant became an engineering-minded vehicle retaining roughly the same form and function of the artillery tractor model - however this design had an open-air cargo bed set over the rear and was used mainly to tow engineering equipment and other larger mission components as needed.
At the start of World War 2 on September 1st, 1939, the French Army benefitted from having taken on both forms of this half-track into service in useful numbers. They were sound and reliable platforms able to undertake a variety of standard and non-standard roles which made them flexible products for even the most inflexible of land armies. The need for the vehicle was so great that both UNIC and Kegresse participated in their large-scale production to help meet demand.
With the Fall of France in June of 1940, many of the French stock of half-tracks found new service under German ownership and these carried the Wehrmacht designation of "Leichter Zugkraftwagen U 304(f)" - the lowercase "f" detailing their French origins. In German service, the type continued its stellar service record and were used in all manner of ways - artillery towing, troop transport, etc... some were even modified with SdKfz 250-style armored superstructures and used in similar frontline battlefield roles as their German counterparts.