The dominant political ideology of the era was Deng Xiaoping Theory, which was accepted by the party in 1978, and he served in various leadership positions, although his paramount power was not overtly reflected in his formal titles. Instead, the formal leaders of the party were a series of younger leaders promoted (and then demoted) by Deng and other influential elders. The most prominent of these were Hu Yaobang (Party Chairman from 1981, General Secretary from 1982, demoted 1987, died 1989), and Zhao Ziyang (Premier from 1980, General Secretary from 1987, demoted and place under house arrest in 1989). They were replaced by Li Peng and Jiang Zemin, who would go on to become prominent members of the third generation of leaders.