crop failures and famines during the 1830s

 This refers to the Tenpo famines, which were nationwide famines occurring between 1833 and 1836. During these years, rice prices soared due to successive crop failures, and many destitute peasants died of starvation. It was to seek relief that peasant uprisings broke out in many areas, thus aggravating the crisis that confronted the Tokugawa government.