Sun Ru
It is not known when Liu Jianfeng was born, but it is known that he was from Langshan (朗山, in modern Zhumadian, Henan). At some point, he became an officer at Zhongwu Circuit (忠武, headquartered in modern Xuchang, Henan) and was stationed at Cai Prefecture (蔡州, in modern Zhumadian), which Langshan belonged to, as part of the effort to resist the major agrarian rebel Huang Chao, serving alongside his Zhongwu Circuit colleague Sun Ru, and both served under Qin Zongquan the military governor of Fengguo Circuit (奉國, headquartered at Cai Prefecture). They continued to serve under Qin after Qin had rebelled against the rule of Emperor Xizong and declared himself emperor.