On October 23, 1991, the four Cambodian factions and representatives of 19 other countries signed a set of agreements in Paris, and a conflict that had run since the late 1970s came to a formal end. The documents provided for a ceasefire, the withdrawal of foreign forces, the return of refugees and the holding of free elections, and they gave the United Nations a role in running the country in the meantime. The fighting stopped.
The war had several layers. Vietnamese forces had entered Cambodia in 1978 and had removed the Khmer Rouge government, and they stayed for a decade, and they were opposed by a coalition of Cambodian groups that included the Khmer Rouge and two non-communist parties, which were supported from outside. A peace process began in the late 1980s with talks in Jakarta and later in Paris, and the withdrawal of Vietnamese troops in 1989 helped to move it forward.
The agreements created the United Nations Transitional Authority in Cambodia, known as UNTAC, which took over the main functions of government, supervised the ceasefire, and organised the election of 1993, which was held with a very large turnout. The task was large. UNTAC was one of the largest and most expensive operations the United Nations had mounted to that point, and it brought in troops, police and civilian staff from dozens of countries.
The election produced a coalition government, and the monarchy was restored in 1993, and a constitution was adopted. The Khmer Rouge refused to take part and fought on for some years before it broke up. Cambodia has since held regular elections and joined the Association of Southeast Asian Nations, and the Paris agreements are still the basis on which the country's modern political settlement is described.