Baku

Qajar Iran de facto · 1789 – October 24, 1813 (from the border data)
Russian Empire de facto · October 23, 1813 – September 14, 1917 (from the border data)
Russia de facto · September 14, 1917 – November 7, 1917 (from the border data)
Russia de facto · December 6, 1917 – April 22, 1918 (from the border data)
Russia de facto · April 28, 1920 – March 12, 1922 (from the border data)
Soviet Union de facto · December 30, 1922 – December 25, 1991 (from the border data)
Azerbaijan de facto · since December 26, 1991 (from the border data)