Admiral Bonard had replaced Vice Admiral Léonard Charner as the head of French forces colonizing in south-east Asia. Charner had already secured three provinces in Cochinchina and Bonard continued this energetic action. He captured Bien-Hoa in December 1861 and then took the key Mekong Delta town of My Tho after a three-day siege. Emperor Tu-Duc was forced to cede the provinces from Saigon to the Cambodian border as permanent French possessions at the Treaty of Saigon on June 5, 1862. (By John Osborne)