The Geneva Conference of 1954 ended France's colonial presence in Vietnam and partitioned the country into two states at the 17th parallel pending unification on the basis of internationally supervised free elections. Ngô Ðình Diệm, a former mandarin with a strong Catholic and Confucian background, was selected as Premier of the State of Vietnam by Bảo Đại. While Diệm was trying to settle the differences between the various armed militias in the South, Bảo Ðại was persuaded to reduce his power. Diệm used a referendum in 1955 to depose Bảo Đại and declare himself President of the Republic of Vietnam (South Vietnam). The Republic of Vietnam (RVN) was proclaimed in Saigon on October 26, 1955. The United States began to provide military and economic aid to the RVN, training RVN personnel, and sending U.S. advisors to assist in building the infrastructure for the new government.