Query: Who is the ruler of the Congo?
Context: The People's Republic of the Congo was a Marxist–Leninist one-party state from 1970 to 1991. Multi-party elections have been held since 1992, although a democratically elected government was ousted in the 1997 Republic of the Congo Civil War and President Denis Sassou Nguesso has ruled for 26 of the past 36 years.