Takasugi played a major role in this civil war and his former "Kiheitai" militia proved its superiority over old-fashioned samurai forces. With a series of quick strikes and the support of Katsura Kogorō, Takasugi achieved victory by March 1865. He became one of the main arbiters of the Chōshū domain's policy and continued to act as the domain's expert on Western military science, devoting his efforts to importing arms and raising troops. These reforms proved to be successful when Chōshū was victorious on four fronts against the "Bakufu's" Second Chōshū expedition on 7 June 1866, with the "Kiheitai" itself securing victory on two fronts. Takasugi's efforts had made a small-scale 'nation in arms' out of Chōshū, giving it a military strength out of proportion to its relatively small size. With its victory over the Tokugawa forces, the military power of the "Bakufu" was discredited, and traditionally rival domains decided to join forces with Chōshū in the subsequent battles which will eventually led to the end of the Tokugawa bakufu and the start of the Meiji Restoration in 1868.