By origin of Gong-Fu, I think you meant formularized and formalised Gong-Fu. Somewhere around 5th Century AD.
Story has it that this formalisation/ formularization of physical fighting skills was started by BodhiDharma, a travelling monk from the "Western Regions"( Some folk lore cites India). He was also the one who started the Zen school/branch of Buddhism in China.