Dieudonné Saive, born in Wandre in 1888, joined FN after high school as a 1906 tool designer, worked at Vickers during World War I, and assisted Browning after inventing a double-stack magazine first tried in an FN 1903. After Browning died at FN in 1926, Saive completed the compact 9mm pistol once Colt patents expired in 1928, yielding the 1934 GP-35 with external hammer and thumb safety that Belgium adopted in 1935.

Germans occupying the plant issued it as the Pistole 640(b) while Saive fled to Britain and started Inglis production in Canada for Allied forces, so both sides carried the same handgun. Over fifty nations later adopted it, Saive also designed the FN 1949 that became the FAL used by more than ninety countries, and FN launched a 17-round American High Power in 2022.