Who ruled Vietnam during World War II?

Initially, the country was led by a man having the surname "Diem." He was a Roman Catholic who was supported by the USA and who was, at least in theory, democratically elected. In the mid-1960s, Diem lost US support and also managed to alienate many in Vietnam, especially Buddhists. He was assassinated in a military coup. After that, power shifted among a cadre of generals: General Minh, General Thieu, and General Khanh were the most prominent. It was General Minh who actually surrendered to the Communists at the end of the war.