By the 1930s French military planners could no longer ignore the obsolescence of their masterpiece FT17 tank from late WWI, and work started on a genuine successor to fill the void. One of the answers they came up with was the R35 light tank, which utilized rolled steel lower and three-piece cast upper hull designs and was armed with the short barreled 37mm gun. It was crewed by two. When hostilities with Nazi Germany burst into life in May 1940 the R35 was right in the front line. While it showed its armor was reliable, the 37mm gun was inadequate when it came to taking out German armor. The Fall of France in June 1940 meant that production of the R35 was curtailed to approximately 1,600 units.