Imam Yahya ibn Muhammad Hamid ad-Din (1869?–1948) ruled during the period when Yemen established its independence; he was assassinated during an uprising. 'Ali 'Abdallah Salih (b.1942) became president of the YAR in 1978, ending a period of upheaval in which his two immediate predecessors were assassinated. Field Marshal 'Abdallah as-Sallal (1920–94) was the first president of the YAR and held power from 1962 until a coup ousted him in 1967. 'Ali Nasir Muhammad al-Hasani (b.1940?) was prime minister of the PDYR in 1980 and president from 1980 to 1986. Haydar Abu Bakr al-'Attas (b.1939) was prime minister of the PDYR during 1985–86.