French Indochina (present day Vietnam) was conquered by France in 1858. It had taken the French slightly more than eight years to make themselves masters of Cochinchina (a protectorate already had been imposed on Cambodia in 1863). It took them 16 more years to extend their control over the rest of the country. They made a first attempt to enter the Red River delta in 1873, after a French naval officer and explorer named Francis Garnier had shown, in a hazardous expedition, that the Mekong River could not serve as a trade route into southwestern China. Garnier had some support from the French governor of Cochinchina, but when he was killed in a battle with Chinese pirates near Hanoi, the attempt to conquer the north collapsed.