General Lin Biao was officially declared Mao's successor in 1969. Mao soon became wary of Lin's increasing power and attempted to undermine him by removing his supporters from high-ranking positions and publicly attacking his views.
The cause of Lin's sudden death in 1971 remains a mystery. The Chinese government's official explanation is that Lin fled to the Soviet Union after his plan to assassinate Mao failed. However, Western historians have suggested that communist party leadership plotted against him because Mao was threatened by the power Lin and the army had amassed.
After Lin's death, high-ranking members of his military were purged, and Zhou Enlai, an ally of Mao, came to power. Lin's death left many Chinese citizens feeling disillusioned, as the lofty ideals of the cultural revolution were reduced to ordinary power struggles.