It is not known when Lu Xisheng was born. His family claimed ancestry from the ruling house of Tian of the Warring States period state Qi, and traced its subsequent ancestry through officials of Han Dynasty, Jin Dynasty, Liu Song, Southern Qi, Liang Dynasty, Chen Dynasty, and Tang Dynasty. Both Lu Xisheng's 5th-ancestor Lu Yuanfang and Lu Yuanfang's son Lu Xiangxian served as chancellors — Lu Yuanfang under the female sovereign Wu Zetian, who interrupted Tang and established her own state of Zhou, and Lu Xiangxian under Wu Zetian's son Emperor Ruizong of Tang and grandson Emperor Xuanzong. Lu Xisheng was descended from Lu Xiangxian's younger brother Lu Jingrong. His grandfather Lu Mengru served under a prefectural prefect, and his father Lu Ao was not listed with any official titles.
Early career
It was said that Lu Xisheng was studious and was good at writing. He particularly understood the I Ching, the Spring and Autumn Annals, and the Tao Te Ching well, and wrote many commentaries. At one point, he served on the staff of Zheng Yuthe prefect of Shang Prefecture, at Zheng's request. After he left his service under Zheng, he became a hermit in Yixing. After a long period of time, he was summoned by the imperial government to serve as You Shiyi, an advisory official at the legislative bureau of government. It was said that at that time the ruling officials were corrupt, and there had been several years of bad harvests, with the situation being particularly severe in the region of Bian and Song Prefectures. Lu realized the severity of the situation and submitted petitions that warned that these conditions would be prime for the appearance of agrarian rebels, but apparently his petition drew no reactions. The next year, as he warned, the agrarian rebel Wang Xianzhi started a major rebellion. Lu later served as the prefect of She Prefecture. Emperor Zhaozong heard of his fame, and recalled him to the imperial government to serve as imperial attendant.
Chancellorship and after chancellorship
In 895, Emperor Zhaozong made Lu Xisheng the deputy minister of census and a chancellor with the designation Tong Zhongshu Menxia Pingzhangshi. However, it was said that Lu did nothing important while being chancellor. He was removed from chancellorship just three months later and made an advisor to the Crown Prince. Later in the year, when Emperor Zhaozong fled the capital Chang'an into the Qinling Mountains due to the attack by the warlords Li Maozhenthe military governor of Fengxiang Circuit and Wang Xingyu the military governor of Jingnan Circuit, Lu followed despite his being ill at the time. He apparently died during flight, and was subsequently given posthumous honors and the posthumous name of Wen.
