Despite his endorsement of violent acts against humans, as described in "Combat Without Weapons", Hartley Leather was a lay reader and freemason. How he wrestled with aggression v. faith is conjectural, but his booklet was innovative when gallantry in self-defense ruled. Historically, the basis for the killing methods he proposed probably first saw light in Britain when the Anglo-Indian, engineer, Edward William Barton-Wright, founded the Bartitsu School of Arms in London in 1898. In 1900, Barton-Wright invited the Japanese jujitsu expert, S. K. Uyenishi, to teach at his school. Uyenishi soon began teaching extreme versions of jujitsu to British officers, before returning to Japan in 1908.
Following the sowing of these first seeds, jujitsu techniques spread throughout the British Isles and abroad. Although Uyenishi had taught his own "Ju-Jutsu" as a recreational activity, it was probably from his jujitsu techniques combined with "Bartitsu" applications that unarmed combat for killing developed.