Zhu Xuan
Zhu Jin was born in 867, during the reign of Emperor Yizong. He was from Xiayi (下邑, in modern Suzhou, Anhui). His older cousin (or, according to some sources, brother) Zhu Xuan was an officer at Tianping Circuit (and would later be military governor), and so he went to serve under Zhu Xuan. He was said to have great ambitions and to be talented in his youth and was the most ferocious warrior in Zhu Xuan's army, but was also said to be violent and cruel.