Sino-Soviet relations from 1969 to 1991
Relations between the People's Republic of China and the Soviet Union underwent significant change from 1969 to 1991, from open conflict to bitter détente to diplomatic partners by 1989. Relations between the Soviet Union (USSR) and Chinese Communist Party (CCP) dated back to the founding of the CCP in Shanghai in 1921, a meeting conducted under the supervision of the Communist International.
Source: Wikipedia — Sino-Soviet relations from 1969 to 1991 (CC BY-SA 4.0)