Wu Sangui had in 1667 submitted a…

Wu Sangui had in 1667 submitted a request to the Kangxi Emperor, asking for permission to be relieved of his duties in Yunnan and Guizhou provinces, on the excuse that he was ill, and the Emperor had approved.

The Kangxi Emperor decides in 1673 to make Wu Sangui, along with the two other princes who had been rewarded with large fiefs in southern and western China, move from their lands to resettle in Manchuria.

As a result, the three revolt.

Thus begins the eight-year civil war known as the Revolt of the Three Feudatories (also known as the San-fan War), with Wu Sangui declaring himself the "All-Supreme-Military Generalissimo".