Li Jing (571 – July 2, 649), courtesy name Yaoshi, posthumously known as Duke Jingwu of Wei (also spelled as Duke of Wey), was a Chinese military general, strategist, and writer who lived in the early Tang dynasty and was most active during the reign of Emperor Taizong. In 630, Li Jing defeated the Göktürks, led by Jieli Khan, with just 3,000 cavalry soldiers in a surprise attack, allowing the Tang Empire to subjugate the Göktürks and reduce them to the status of a vassal under the Tang Empire. Li Jing and Li Shiji are considered the two most prominent early Tang generals. During the Sui dynasty Li Jing was born in 571, during the Sui dynasty's predecessor state Northern Zhou. His clan was from the Chang'an region. His grandfather Li Chongyi (李崇義) served as a provincial governor during the Northern Wei, and his father, Li Quan (李詮), served as a commandery governor during Sui. In his youth, Li Jing was said to be handsome and ambitious, and was talented both in literary and military matters. His maternal uncle was the Sui general Han Qinhu (韓擒虎), and it was said that Han was impressed by his talent, stating, "You are the only person that I can talk to about Sun Tzu's and Wu Qi's strategies." Early in his career, Li Jing served as a minor county official for Chang'an county—one of the two counties within Chang'an, which served as Sui's capital. He later served as a low level official within the imperial administration, and it was said that he impressed both the prime minister Yang Su and the important minister Niu Hong (牛弘). Near the end of the reign of Emperor Yang, Li Jing served as the vice prefect of the Mayi Commandery (馬邑, roughly modern Shuozhou, Shanxi), when he served under the general Li Yuan the Duke of Tang, who was in charge of the nearby important city of Taiyuan (太原, in modern Taiyuan, Shanxi) against Eastern Tujue forces. Li Jing came to suspect that Li Yuan was plotting a rebellion, and therefore pretended to commit a crime and asked to be locked up and delivered to Emperor Yang, who was then at Jiangdu (江都, in modern Yangzhou, Jiangsu). However, he was first delivered to Chang'an, and then, as nearly the entire Sui state was engulfed in agrarian rebellions at that time, there was no way to deliver him