When the Vietnamesesovereignsbegan the active persecution of Christian missionaries,Franceinvaded southern Vietnam and by 1862 had captured Saigon (nowHo Chi MinhCity),Bien Hoa, andVinh Long. In theTreaty of Saigon, Phan Thanh Gian ceded Gia Dinh and Dinh Thong (present-day My Tho), in the...