Muhammad bin Tughlaq died in 1351 while trying to chase and punish people in Gujarat who were rebelling against the Delhi Sultanate. He was succeeded by Firuz Shah Tughlaq (1351–1388), who tried to regain the old kingdom boundary by waging a war with Bengal for 11 months in 1359. However, Bengal did not fall. Firuz Shah ruled for 37 years. His reign attempted to stabilize the food supply and reduce famines by commissioning an irrigation canal from the Yamuna river. An educated sultan, Firuz Shah left a memoir. In it he wrote that he banned the practice of torture, such as amputations, tearing out of eyes, sawing people alive, crushing people's bones as punishment, pouring molten lead into throats, setting people on fire, driving nails into hands and feet, among others. He also wrote that he did not tolerate attempts by Rafawiz Shia Muslim and Mahdi sects from proselytizing people into their faith, nor did he tolerate Hindus who tried to rebuild temples that his armies had destroyed. As punishment for proselytizing, Firuz Shah put many Shias, Mahdi, and Hindus to death (siyasat). Firuz Shah Tughlaq also lists his accomplishments to include converting Hindus to Sunni Islam by announcing an exemption from taxes and jizya for those who convert, and by lavishing new converts with presents and honours. Simultaneously, he raised taxes and jizya, assessing it at three levels, and stopping the practice of his predecessors who had historically exempted all Hindu Brahmins from the jizya. He also vastly expanded the number of slaves in his service and those of Muslim nobles. The reign of Firuz Shah Tughlaq was marked by reduction in extreme forms of torture, eliminating favours to select parts of society, but also increased intolerance and persecution of targeted groups.