Meiji's 1868 oath Westernized Japan after Perry forced the gates
The Meiji Restoration of 1868 restored practical imperial rule under Emperor Meiji and drove rapid Westernizing reform after Tokugawa crises and Perry's American expedition shattered sakoku isolation under unequal treaties. On 3 January 1868 the emperor declared power returned; the Charter Oath set goals.
Under the Tokugawa order, rank was inherited and the ladder was steep: emperor and court on top, then the shōgun with his senior councillors and the daimyō, then graded samurai, farmers, artisans and merchants. Samurai households made up only about 5 to 6 percent of a population near 30 million, and perhaps one in fifty of them counted as upper samurai. Power rested on land measured in koku of rice; by 1650 the shōgun held about 4.2 million koku outright, while roughly 100 tozama lords, descended from enemies at Sekigahara, shared just under 38 percent of the national yield.
The system was strained long before foreign ships appeared. Fixed rice stipends left samurai exposed to market swings and coin debasement, and many sank into debt. The shogunate's gold shortfall grew from a small annual gap around 1800 to more than half a million ryō by 1837. Mizuno Tadakuni's Tenpō Reforms of 1841 to 1843 tried austerity and sumptuary laws amid famine and unrest such as the Osaka revolt, yet mainly exposed a rift between the shogunate and the great lords.
Ideas were shifting too. A Shintō revival and Dutch studies both drew scholars away from China as the intellectual centre, and the Mito School shaped the slogan fukoku kyōhei, a rich country with a strong army. Sakuma Shōzan summed up a pragmatic mood as Eastern ethics paired with Western science; he cast cannon, built a camera, compiled a Japanese-English dictionary and taught more than 5,000 pupils in Edo, including Katsu Kaishū and Yoshida Shōin.
After the 1868 declaration, holdouts fought on in the Boshin War and the brief Republic of Ezo, but by the 1870s imperial authority was secure. The new state scrapped the old currency, dissolved the domains and finally erased samurai status, surviving the Saga and Satsuma revolts. The Meiji Constitution of 1889 then lasted until the Allied occupation after World War II.
Source: Meiji Restoration
