But, after feigning mental illness in May 1901, he managed to escape from a mental hospital at Saint Petersburg with the help of a Polish physician, Władysław Mazurkiewicz, and others, fleeing to Galicia, then part of Austria-Hungary, and thence to Leytonstone in London, staying with Leon Wasilewski and his family. During this period, almost all parties in Russian Poland and Lithuania took a conciliatory position toward the Russian Empire and aimed at negotiating within it a limited autonomy for Poland. Piłsudski's PPS was the only political force prepared to fight the Empire for Polish independence and to resort to violence to achieve that goal. On the outbreak of the Russo-Japanese War (1904–1905), in the summer of 1904, Piłsudski traveled to Tokyo, Japan, where he tried unsuccessfully to obtain that country's assistance for an uprising in Poland. He offered to supply Japan with intelligence in support of its war with Russia, and proposed the creation of a Polish Legion from Poles, conscripted into the Russian Army, who had been captured by Japan. He also suggested a "Promethean" project directed at breaking up the Russian Empire, a goal that he later continued to pursue. Meeting with Yamagata Aritomo, he suggested that starting a guerrilla war in Poland would distract Russia and asked for Japan to supply him with weapons. Although the Japanese diplomat Hayashi Tadasu supported the plan, the Japanese government, including Yamagata, was more skeptical. Piłsudski's arch-rival Roman Dmowski travelled to Japan. He argued against Piłsudski's plan, endeavoring to discourage the Japanese government from supporting a Polish revolution, which Dmowski felt doomed to failure. Dmowski, a Polish patriot, remained Piłsudski's political arch-enemy to the end of Piłsudski's life. In the end, the Japanese offered Piłsudski much less than he hoped; he received Japan's help in purchasing weapons and ammunition for the PPS and their combat organisation, and the Japanese declined the Legion proposal. In the fall of 1904, Piłsudski formed a paramilitary unit (the Combat Organization of the Polish Socialist Party, or "bojówki") aiming to create an armed resistance movement against the Russian authorities. The PPS organized an increasing numbers of demonstrations, mainly in Warsaw; on 28 October 1904, Russian Cossack cavalry attacked a demonstration, and in reprisal, during a demonstration on 13 November Piłsudski's paramilitary opened fire on Russian police and military.