On the early morning of July 2, 626 CE, the fate of the Tang Dynasty was sealed at the Xuanwu Gate in northern Chang’an (modern-day Xi’an). At this pivotal moment, Li Shimin, who would later become Emperor Taizong, led a small but determined group of loyal soldiers to stage a coup. Tensions had long simmered between Li Shimin and his elder brother, Li Jiancheng, who had been designated heir apparent. Supported by their younger brother Li Yuanji,