Denis Sassou Nguesso is a Congolese politician and former military officer. He became president of the Republic of the Congo in 1997. He served a previous term as president from 1979 to 1992. During his first period as president, he headed the Congolese Party of Labour (PCT) for 12 years. He introduced multiparty politics in 1990, but was stripped of executive powers by the 1991 National Conference, remaining in office as a ceremonial head of state. He stood as a candidate in the 1992 presidential election but placed third.