 Under the orders of Napoleon III of France, Rigault de Genouilly's gunships attacked the port of Đà Nẵng in 1858, causing significant damage, yet failed to gain any foothold, in the process being afflicted by the humidity and tropical diseases.De Genouilly decided to sail south and captured the poorly defended city of Gia Định (present-day Ho Chi Minh City).From 1859 to 1867, French troops expanded their control over all six provinces on the Mekong delta and formed a colony known as Cochinchina.