Emperor Taizong Li Shimin (598–649), the second emperor of the Tang Dynasty, is widely regarded as one of China's greatest rulers. As a prince, he was instrumental in his father Li Yuan's rebellion against the Sui Dynasty, and after seizing power through the Xuanwu Gate Incident, he inaugurated the 'Reign of Zhenguan,' a golden age of Chinese governance.
Taizong was famous for accepting candid criticism from his ministers, especially Wei Zheng, whom he called his 'mirror.' He lightened taxes, promoted agriculture, and perfected the imperial examination system. Militarily, he defeated the Eastern Turkic Khanate and earned the title 'Heavenly Khan' from Central Asian peoples. His cosmopolitan empire attracted scholars and merchants from across Eurasia, making Chang'an the most international city of the medieval world. The Reign of Zhenguan became the enduring model of ideal governance in Chinese political thought.
