上海公共租界巡捕房
The origins of modern close-quarters combat as well as SWAT tactics lie in the policing methods pioneered by Assistant Commissioner William E. Fairbairn in the Shanghai Municipal Police of the International Settlement (1854–1943). After the May Thirtieth Movement riots, Fairbairn was charged with developing an auxiliary squad for riot control and aggressive policing. After absorbing the most appropriate elements from a variety of martial-arts experts, from China, Japan and elsewhere, he condensed these arts into a practical combat system he called Defendu.