Complex sentence: Karmal was made Chairman of the Revolutionary Council and Chairman of the Council of Ministers on 27 December 1979, he would retain his Council of Ministers chairmanship until 1981 when he was succeeded in office by Sultan Ali Keshtmand.
Split into simpler sentences: Karmal was made Chairman of the Revolutionary Council and Chairman of the Council of Ministers on 27 December 1979. He would retain his Council of Ministers chairmanship until 1981, when he was succeeded in office by Sultan Ali Keshtmand.