In addition to formally closing the book on the Safavids, one of the three Islamic “Gunpowder Empires” of the early modern (16th-18th century) period, Nader Shah also helped hasten the downfall of a second: India’s Mughal dynasty, and he did it in one dramatic and brutally violent invasion in the late 1730s. The Shiʿa Safavids and Sunni Mughals had been close allies at one time. Safavid military aid helped Babur found the Mughal dynasty in 1526 and helped Babur’s son, Humayun, return to the throne in 1555 after he’d been forced out of power several years earlier. But as the Safavids had waned and the Mughals had gotten stronger, the two empires began to feud over the cities of Kandahar and Kabul. Nader conquered Kandahar in 1738, as he was chasing the remnants of the Ghilzai Afghans out of Iran. When those Afghans sought refuge in Mughal territory, and the Mughals didn’t take any steps to prevent it, Nader decided to keep marching his army right on into northern India.