Flag on the Nguyễn dynasty, 1920�?945 Just after Vietnam lost Gia Định, the island of Poulo Condor, and three southern provinces to France Together with the Treaty of Saigon among the Nguyễn dynasty and France in 1862, quite a few resistance actions inside the south refused to acknowledge the treaty https://franciscocnwel.bloguetechno.com/little-known-facts-about-việt-nam-66290647