In the post war-era The Majestic served as the first headquarters of UNESCO,[11] from September 16, 1946[3] until 1958, when it was converted into a conference center for the French Ministry of Foreign Affairs,[12] known as the International Conference Center. The Organisation for Economic Co-operation and Development was founded at the hotel in 1960[13] and it was the location for the signing of the Paris Peace Accords on January 27, 1973[14] that ended American involvement in the Vietnam War.[4] Later, on October 23, 1991, the 1991 Paris Peace Accords, which ended the Cambodian-Vietnamese War and Khmer Rouge civil war, were also signed there.