The Grande Puissance - High Power - was John Browning's last firearms design. In fact, he only began the design; it was taken to completion by his protege Dieudonné Saive at FN in Belgium. It was the best military handgun of the time, with a double-stack 13-round magazine capacity, and chambered for the 9x19mm cartridge. Belgium was the First Nation to adopt it for military service, purchasing 1,000 guns for field trials and approving them in 1935 for standard issue as the GP-35.

The Belgian trials guns have a distinctive oval ejection port, which would be changed on production models. They were also fitted with flat board shoulder stocks and tangent sights adjustable up to 500 meters. These features would last until German occupation of the FN factory complex during World War Two, when the guns were simplified under German occupation production.