Hanoi

Vietnam de facto · 1789 – June 5, 1884 (from the border data)
France de facto · June 6, 1884 – October 16, 1887 (from the border data)
French Indochina de facto · October 17, 1887 – March 9, 1945 (from the border data)
Japan de facto · December 8, 1941 – September 2, 1945 Military occupation (from the border data)
Vietnam de facto · March 11, 1945 – August 31, 1945 (from the border data)
North Vietnam de facto · September 2, 1945 – July 2, 1976 (from the border data)
Vietnam de facto · since July 2, 1976 (from the border data)