The human presence in Japan dates back to about 17,000 years. Buddhism was introduced around 700CE, during the Asuka Period, and this started a high cultural age inspired by Chinese culture. The Kamakura Period, in 1185CE, started with a conflict between warring clans and ended with the rise of the Minamoto Clan, the Shogunate, and the Samurai class. During this period, the Mongols tried unsuccessfully to annex the archipelago twice, once in 1274 and again in 1281. The Muromachi Period, starting in 1333, was a period of significant civil conflict and the introduction of European culture through trade and missionary activities. The end of this period witnessed the rise of the Tokugawa Shogunate, the persecution of Christians, and the isolation of Japan. The nearly 300 years of peace following was known as the Edo period. In 1853, American Commodore Matthew Perry arrived in Edo harbor with a fleet of American War Ships. Japan opened itself up to trade at that moment, but the Meiji Emperor refused to allow Japan to end up partitioned like China, so he began an aggressive modernization of the country which ended the Shogun and Samurai period, but also helped Japan become an imperial power in Asia through victory in a series of wars with China and Russia. Japan allied with the Allies in WWI, but became aggressive with China and other neighbors during the Great Depression. By 1941, Japan was a world power and decided to test its power in a war with the United States. The war led to defeat for Japan and a modernization and democratization period that continues today.