Emperor Ai of Tang
In 904, Zhu forced Emperor Zhaozong to move the capital from Chang'an to Luoyang, which was even more firmly under his control. Later that year, fearing that the adult Emperor Zhaozong would try to rise against him while he was away on campaigns against other warlords, he had Emperor Zhaozong assassinated. Bypassing Li Yu and the other older princes, he had an edict issued in Emperor Zhaozong's name creating Li Zuo crown prince and changing his name to Li Chu. Shortly after, Li Chu took the throne (as Emperor Ai). Empress He, who survived the assassination, was honored empress dowager.
Five Dynasties and Ten Kingdoms period
Traditionally, the era started with the fall of the Tang dynasty in 907 AD and ended with the founding of the Song dynasty in 960. Many states had been "de facto" independent kingdoms long before 907. After the Tang had collapsed, the kings who controlled the Central plain crowned themselves as emperors. War between kingdoms occurred frequently to gain control of the central plain for legitimacy and then over the rest of China. The last of the Five Dynasties and Ten Kingdoms states, the Northern Han, was not vanquished until 979.