Immigrants in troubled times are prosperous.

The Anshi Rebellion occurred in the prosperous Tang Dynasty for the following reasons:

1. Personal ambition: An Lushan himself has extremely high political ambition. He hoped to seize the throne through rebellion and realize his desire for power.

2. Corruption in the imperial court: Although the Tang Dynasty at that time seemed prosperous on the surface, in fact, internal corruption was serious, officials were corrupt and the people lived in poverty, which gave An Lushan the opportunity to rebel.

3. Favor for Xuanzong: An Lushan was a favorite of Xuanzong in the Tang Dynasty, and his power even surpassed that of some prime ministers, which gave him enough influence and resources to rebel in the DPRK.

4. Frontier pressure: In the Tang Dynasty, the frontier was always threatened by strong enemies such as Khitan and Turkic, which forced the imperial court to maintain a strong military force to deal with foreign enemies, which undoubtedly increased the financial pressure of the imperial court and the burden of the people.

5. Ethnic contradictions: The Tang Dynasty was a multi-ethnic country, and there were deep contradictions and conflicts between the Han nationality and ethnic minorities, which provided opportunities for the Anshi Rebellion.

Generally speaking, An Lushan was able to rebel in the prosperous Tang Dynasty, mainly because he used the internal contradictions and external pressure of the imperial court, as well as his own ambition and power, and successfully launched the rebellion.