The State of Vietnam referendum of 1955 determined the future form of government of the State of Vietnam, the nation that was to become the Republic of Vietnam (widely known as South Vietnam). It was contested by Prime Minister Ngô Đình Diệm, who proposed a republic, and former emperor Bảo Đại. Bảo Đại had abdicated as emperor in 1945 and at the time of the referendum held the title of head of state. Though published counts showed Diệm winning the election with 98.2% of the vote, the referendum was widely marred by electoral fraud. In the capital, Saigon, Diệm was credited with more than 600,000 votes, although only 450,000 people were on the electoral roll. He accumulated tallies in excess of 90% of the registered voters, even in rural regions where opposition groups prevented voting.