In 1858, France launched an attack on Đà Nẵng, starting its invasion of Vietnam. In 1867, France completed its conquest of southern Vietnam (Cochinchina), comprising the provinces of Biên Hoà, Gia Định, Định Tường, Vĩnh Long, An Giang, and Hà Tiên. To consolidate the newly established colony, on 23 February 1868, Lagrandière, Governor of Cochinchina, held a ceremony to lay the foundation stone of a new palace to replace the old wooden palace built in 1863. The new palace was designed by Hermite, who was also the architect of the Hong Kong City Hall. The first cubic stone, measuring 50 cm