was a after Bunsei and before Kōka. The period spanned from December 1830 through December 1844. The reigning emperor was .
Introduction
Change of era
December 10, 1830 () : In the 13th year of Bunsei, the new era name of Tenpō (meaning "Heavenly Imperial Protection") was created to mark the disasters of a great fire in Edo and an earthquake at Kyoto. The new era name was created from an hortatory aphorism: "Respect and worship the Ways of heaven. Eternally keep the Mandate of Heaven" (欽崇天道、永保天命).
The Tenpō era is often described as the beginning of the end of bakufu government. Though the era accomplished much through its reforms, and also culturally speaking, the injury inflicted on the Tokugawa system of government during the Tenpō period was unparalleled. Public order and dissatisfaction with government was a main issue, but the bakufu was not entirely at fault for the stir amongst the people. For example, the failure of crops in 1833, which soon became a lengthy disaster endured for over four years and was called the Great Tenpō famine. It was caused mainly by poor weather conditions. Because crops could not grow under these circumstances, prices began to skyrocket. These dire circumstances sparked many rebellions and riots across Japan over the course of the Tenpō years. Weary and desperate for someone to blame, the people rose up against the government, and Ōshio Heihachirō, known for leading one of the largest rebellions, made a statement to implicate "the natural disasters as sure signs of Heavens's discontent with the government". Mizuno Tadakuni's reforms were meant to remedy these economic issues, but the reforms could not rescue the bakufu from its ultimate collapse.
The shogunate rule during the Tenpō era was that of Tokugawa Ieyoshi, the 12th shōgun of the bakufu government. His reign lasted from 1837 to 1853. During this time, many factors appeared to have seen to the decline of his health: namely, the great and devastating famine, the many rebellions rising up against the bakufu, and the swift advance of foreign influence.
Great Tenpō Famine
The Great Tenpō famine of the 1830s was a devastating period in which the whole of Japan suffered rapidly decreasing temperatures and loss of crops, and in turn, merchant prices began to spike. Many starved to death during this grim time: "The death rate for a village in the northeast rose to thirty-seven per thousand and that for the city of Takayama was nearly forty-five". As crops continued to decline in the countryside, prices increased, and a shortage of supplies left people competing to survive on meager funds. The rising expense of rice in particular, a staple food of the Japanese, was a firm blow to both the economy and the people, who starved because of it. Some even resorted to "eating leaves and weeds, or even straw raincoats".
The samurai also suffered the effects of the famine, dealing with lower wages from the Japanese domain governments in anticipation of fiscal shortfalls to come. To further the already dire conditions of the famine, illness eventually began to spread, and many who were starving could not resist pestilences such as smallpox, measles and influenza. Thousands died from hunger alone at the peak of the crisis in 1836–1837.
Rebellion
One of the rebellions sparked by the Great Tenpō famine was the Ōshio Heihachirō Rebellion. The man for whom it was named led an attempted revolt in the 1830s, and was granted the label of yonaoshi daimyojin, or "world saviour", for his attempts at moral restoration. Formally a police officer and scholar, Ōshio Heihachirō (1792-1837) had requested help from Osaka city commissioners and otherwise wealthy merchants in 1837, only to be met with indifference. Shocked by his lack of success in the endeavour, Ōshio instigated an uprising to oppose those who had refused their aid. With approximately 300 followers, including poor townsfolk and peasants from various villages, Ōshio set fire to one-fifth of Osaka city. But the rebellion was suppressed in short order, forcing Ōshio to a quick end in which he committed suicide.
The scholar Ikuta Yorozo (1801–1837) also instigated a rebellion from similar roots as that of Ōshio Heihachirō. Ikuta had opened a school for the education of adolescents, consisting mostly of peasants. Having also suffered from the Great Tenpō Famine, Ikuta despaired the lack of aid local bureaucrats were willing to provide, and in 1837, he assembled a band of peasants in retaliation. Together they launched an attack on the bureaucrats, which met with devastating results and ended with Ikuta taking his own life.