China began developing nuclear weapons in the late 1950s with help from the Soviet Union.
Although Soviet assistance ended in 1960, Beijing pressed on with its nuclear plans with the aim of guaranteeing national security and boosting China's prestige on the international stage.
It carried out the first of its 46 nuclear tests in October 1964.
China is currently estimated to have about 400 nuclear weapons in total, of which 20 are long-range intercontinental ballistic missiles (ICBM) with ranges of 13,000km. It also has about 60 medium-range missiles and 150 bomber aircraft.