同塔省
Prior to 1975, Cao Lãnh was the capital of Kiến Phong province, in the Mekong Delta region of South Vietnam. In February 1976, Kiến Phong was merged with Sa Đéc Province to become Đồng Tháp Province. Sa Đéc became the capital city of the new province. Cao Lãnh replaced Sa Đéc as the capital on April 24, 1994, and became a city in October 2007.