In 842 BC, the nobles revolted against the corrupt King Li of Zhou, overthrowing him the following year, and the country fell into turmoil. The Xirong tribes used the opportunity to rebel against the Zhou dynasty, attacking and exterminating the senior branch of Yíng clan at Quanqiu, leaving the cadet branch at Qinyi the only surviving Yíng clan in the west. After King Xuan of Zhou ascended the throne in 827 BC, he made Qin Zhong, Feizi's great grandson, the commander of his forces in the campaign against Xirong. Two years later in 822 BC, Qin Zhong was killed in battle, was succeeded by his eldest son Duke Zhuang. To commemorating Qin Zhong's loyalty, King Xuan summoned Duke Zhuang and his four younger brothers and gave them 7,000 soldiers. The Qin brothers successfully defeated the Rong and recovered their lost patrimony formerly held by the deceased branch of Yíng clan, and King Xuan further awarded them the territory of Quanqiu. Duke Zhuang moved his seat from Qinyi to Quanqiu, and had three sons. When he died in 778 BC, his eldest son Shifu wanted to stay fighting the Xirong and avenge their grandfather, turning down the succession, so his second son Duke Xiang ascended as the clan leader. Soon afterwards in 777 BC, Duke Xiang married his younger sister Mu Ying to a Rong leader called King Feng (豐王), in an apparent attempt to make peace. The following year he moved the Qin capital eastward from Quanqiu to Qian (汧, in present-day Long County, Shaanxi), but Quanqiu soon fell to the Rong again after he left. His older brother Shifu, who led the defence of Quanqiu, was captured by the Rong but was released a year later.