The long answer begins in 1948, in the aftermath of World War 2 when the country was recovering from years of turmoil, struggling to create exports to earn foreign exchange, and experiencing rationing of resources so that priority projects (such as construction) could be completed.
The Land Rover’s roots
The rationing of resources had implications on the production of Rover’s established pre-war models, as did the fall in demand of luxury cars in the post-war economy. Models such as the Rover 10, pictured below, weren’t in vogue anymore, and new models were needed to plug this gap.
A 1939 Rover 10 Fixed Head Coupe, used under Creative Commons and linked to source
Maurice Wilks, the chief designer at Rover, designed a utilitarian vehicle with an emphasis on agricultural usage. The logic was that a rugged and sturdy vehicle would better suit the demands of the populace than the priority on aesthetics which had existed through the war. Prototypes and pre-production models of the Land Rover proved themselves in testing, and entered full production in 1948.
A 1951 Series 1 Land Rover, used under Creative Commons and linked to source