Development of the U-SH 405 began in the late 1950’s, after Landsverk and Daimler-Benz formed a cooperation to further develop the Unimog 404 truck into a family of different military vehicles, ranging from APCs to dedicated tank hunters. Development was initially headed by the Germans, but in 1958, Landsverk took over the lead role in its development.

As part of the ongoing development, Landsverk came up with a dedicated tank hunter variant of the vehicle in 1960, fitted with a pair of Oerlikon 81mm rocket launchers, originally developed for aircraft and helicopter use. A single prototype of the machine was built and trialed, but no production orders were issued.

However, the APC version of the U-SH 405 saw more success, being ordered by the Belgian armed forces in limited numbers. Despite placing an order for around two dozen vehicles, due to various geopolitical reasons, Belgium only received fewer than half of the machines initially ordered. The remainder of the machines built, but not shipped to Belgium were later on sold to the Irish military in the early 1970’s, which used the vehicle until 1978 before retiring it.