In 725, Emperor Xuanzong created Li Ze the Prince of Yong, and in 727 gave him the honorary title as the commandant at Jing Prefecture (荊州, roughly modern Jingzhou, Hubei).
With the empire's transportation network disrupted by An's rebellion, the taxes and levies of the region south of the Huai River were all sent to Jiangling, allowing Li Lin access to a great amount of wealth and ability to conscript tens of thousands of soldiers.
His son Li Yang (李瑒) the Prince of Xiangcheng was said to be brave and studied in military matters, and his strategist Xue Liu (薛鏐) suggested to him that given the amount of wealth and territory he had, he should occupy Jinling (金陵, modern Nanjing), take over all of the territory south of the Yangtze River, and establish a separate regime similar to Eastern Jin.
This alarmed Li Xian, who claimed to be ill and resigned, and then reported to Emperor Suzong's then-location at Pengyuan (彭原, in modern Qingyang, Gansu).
Around the new year 757, Emperor Suzong commissioned Gao as the military governor of Huainan Circuit (淮南, headquartered in modern Yangzhou, Jiangsu), and another general, Lai Tian (來瑱), as the military governor of Huainan West Circuit (淮南西道, headquartered in modern Zhumadian, Henan), and instructed them to, along with Wei Zhi (韋陟) the military governor of Jiangdong Circuit (江東, headquartered in modern Suzhou, Jiangsu), to prepare to resist Li Lin.
Li Xiyan (李希言) the governor of Wu Commandery (roughly modern Suzhou) then sent him a letter that treated him as an equal and addressed him by name, inquiring as for the reason for him to be heading east.
Meanwhile, Gao, Lai, and Wei rendezvoused at Anlu (安陸, in modern Xiaogan, Hubei) and public declared their intent to suppress Li Lin's rebellion.
Li Lin and Gao fled to Poyang (鄱陽, in modern Shangrao, Jiangxi) and gathered military supplies there, intending to flee to Lingnan.