that survived to the 19th century originated in this era, declaring themselves to be the blood of one of the four ancient noble clans: Minamoto, Taira, Fujiwara and Tachibana. In most cases, however, it is difficult to prove these claims. Tokugawa shogunate After the Battle of Sekigahara, when the Tokugawa shogunate defeated the Toyotomi clan at summer campaign of the Siege of Osaka in 1615, the long war period ended. During the Tokugawa shogunate, samurai increasingly became courtiers, bureaucrats, and administrators rather than warriors. With no warfare since the early 17th century, samurai gradually lost their military function during the Tokugawa era (also called the Edo period). By the end of the Tokugawa era, samurai were aristocratic bureaucrats for the daimyōs, with their daishō, the paired long and short swords of the samurai (cf. katana and wakizashi) becoming more of a symbolic emblem of power rather than a weapon used in daily life. They still had the legal right to cut down any commoner who did not show proper respect , but to what extent this right was used is unknown. When the central government forced daimyōs to cut the size of their armies, unemployed rōnin became a social problem. Theoretical obligations between a samurai and his lord (usually a daimyō) increased from the Genpei era to the Edo era. They were strongly emphasized by the teachings of Confucius and Mencius, which were required reading for the educated samurai class. The leading figures who introduced Confucianism in Japan in the early Tokugawa period were Fujiwara Seika (1561–1619), Hayashi Razan (1583–1657), and Matsunaga Sekigo (1592–1657). The conduct of samurai served as role model behavior for the other social classes. With time on their hands, samurai spent more time in pursuit of other interests such as becoming scholars. He was given an honorific title and was called 'Obuke-sama'. Modernization The relative peace of the Tokugawa era was shattered with the arrival of Commodore Matthew Perry's massive U.S. Navy steamships in 1853. Perry used his superior firepower to force Japan to open its borders to trade. Prior to that only a few harbor towns, under strict control from the shogunate, were allowed to participate in Western trade, and even then, it was based largely on the idea of playing the Franciscans and Dominicans against one another (in exchange for the crucial arquebus technology, which in turn was a major contributor to the downfall