was a major city-wide riot which erupted in Tokyo on 5 September 1905 in protest of the terms of the Treaty of Portsmouth, which ended the Russo-Japanese War of 1904-1905. Although the Imperial Japanese Navy had decisively defeated the Imperial Russian Navy at the Battle of Tsushima, and the Imperial Japanese Army had taken Port Arthur and had won a major victory over the Imperial Russian Army at the Battle of Mukden, Japanese forces were overextended in Manchuria, and the Japanese economy could no longer sustain a prolonged war effort. Ignorant of the actual war situation, a diverse assortment of activist groups called for a rally at Hibiya Park in central Tokyo to protest what they saw as the humiliating terms of the Treaty of Portsmouth, announced earlier that day. The protesters were e