His older brother Liu Shanbo (劉山伯) was not pleased with this, and often rebuked him, stating, "You are careless with your friendships, and one day you will destroy our clan."
Liu Wuzhou therefore left home and went to the Sui dynasty's eastern capital Luoyang, where he served under the general Yang Yichen.
During Yang's participation of the campaigns against Goguryeo, Liu Wuzhou, on account of his accomplishments, was made a Xiaowei (校尉)—an army officer rank just below a general.
He then took leave on account of illness, but when the local gentry came visiting him, he invited them to a feast and declared his intent to rebel; they agreed to join him.
He then captured Loufan Commandery (樓煩郡, part of modern Xinzhou) and pillaged Fenyang Palace (汾陽宮)—one of the numerous subsidiary palaces that Emperor Yang built around the empire—and took the ladies in waiting and gave them to Eastern Tujue's Shibi Khan Ashina Duojishi as a tribute; in return, Ashina Duojishi sent him horses.
Liu Wuzhou, however, launched a campaign against Tang himself in late spring 619, with collateral support by Eastern Tujue forces.
The mounting defeats concerned Tang's Emperor Gaozu, and he sent one of his senior advisors, Pei Ji, with a sizeable army to face Liu.
Liu then moved his capital from Mayi to Taiyuan, and soon, Song captured Jin (晉州) and Gui (澮州, together roughly modern Linfen, Shanxi) as well, and Pei was unable to resist.
Meanwhile, however, another Tang army, commanded by Emperor Gaozu's cousin Li Xiaoji (李孝基) the Prince of Yong'an, assisted by another cousin, Dugu Huai'en (獨孤懷恩) and two other officials, Yu Yun (于筠) and Tang Jian (唐儉), was attacking Liu's ally Lü Chongmao (呂崇茂), then at Xia (夏縣, in modern Yuncheng, Shanxi).
When Yuchi and Xun then sought to aid another ally, Wang Xingben (王行本), a Sui general still holding out against Tang at Pufan (蒲反, in modern Yuncheng as well), but they were defeated by Li Shimin and forced to withdraw; Wang subsequently was forced to surrender in spring 620, and Emperor Gaozu executed him.
Later in spring 620, Liu Wuzhou attacked Tang's Lu Prefecture (潞州, roughly modern Changzhi, Shanxi), and while he was initially successful, he was unable to capture its capital.
Later, Huang Ziying, while ordered to protect the roads of supplies, was assaulted and killed by Tang general Zhang Dezheng (張德政).