Tonkin campaign

The Tonkin campaign was an armed conflict fought between June 1883 and April 1886 by the French against, variously, the Vietnamese, Liu Yongfu's Black Flag Army and the Chinese Guangxi and Yunnan armies to occupy Tonkin (northern Vietnam) and entrench a French protectorate there. The campaign, complicated in August 1884 by the outbreak of the Sino-French War and in July 1885 by the Cần Vương nationalist uprising in Annam (central Vietnam), which required the diversion of large numbers of French troops, was conducted by the Tonkin Expeditionary Corps, supported by the gunboats of the Tonkin Flotilla. The campaign officially ended in April 1886, when the expeditionary corps was reduced in size to a division of occupation, but Tonkin was not effectively pacified until 1896.

Nine years after Francis Garnier's unsanctioned attempt to conquer Tonkin was cut short by the French government in 1873, French and Vietnamese troops clashed in Tonkin on 25 April 1882, when Commandant Henri Rivière seized the citadel of Hanoi with a small force of marine infantry.

After a lull of several months, the arrival of reinforcements from France in February 1883 allowed Rivière to mount a campaign to capture the citadel of Nam Định (27 March 1883). The Capture of Nam Định was strategically necessary for the French, to secure their communications with the sea.

During Rivière's absence at Nam Định with the bulk of his forces, chef de bataillon Berthe de Villers defeated a Vietnamese attack on the French positions at Hanoi by Prince Hoàng Kế Viêm at the Battle of Gia Cuc (27 and 28 March 1883).

Although these early actions deserve to be considered part of the Tonkin campaign, the campaign is conventionally considered to have begun in June 1883, in the wake of the decision by the French government to despatch reinforcements to Tonkin to avenge Rivière's defeat and death at the hands of Liu Yongfu's Black Flag Army at the Battle of Paper Bridge on 19 May 1883. These reinforcements were organised into a Tonkin Expeditionary Corps, which was placed under the command of général de brigade Alexandre-Eugène Bouët (1833–87), the highest-ranking marine infantry officer available in the French colony of Cochinchina.

The French position in Tonkin on Bouët's arrival in early June 1883 was extremely precarious. The French had only small garrisons in Hanoi, Haiphong and Nam Định, isolated posts at Hon Gai and at Qui Nhơn in Annam, and little immediate prospect of taking the offensive against Liu Yongfu's Black Flags and Prince Hoàng Kế Viêm's Vietnamese. Bouët's first step was to withdraw the isolated French garrisons of Qui Nhơn and Hon Gai. He had also been authorised to abandon Nam Định at need, but he decided to try to defend all three major French posts. During June, the French dug in behind their defences and beat off half-hearted Vietnamese demonstrations against Hanoi and Nam Định.

The early arrival of reinforcements from France and New Caledonia and the recruitment of Cochinchinese and Tonkinese auxiliary formations allowed Bouët to hit back at his tormentors. On 19 July chef de bataillon Pierre de Badens, the French commandant supérieur at Nam Định, attacked and defeated Prince Hoàng Kế Viêm's besieging Vietnamese army, effectively relieving Vietnamese pressure on Nam Định.

The arrival of Admiral Amédée Courbet in Ha Long Bay in July 1883 with substantial naval reinforcements further strengthened the French position in Tonkin. Although the French were now in a position to consider taking the offensive against Liu Yongfu, they realised that military action against the Black Flag Army had to be accompanied by a political settlement with the Vietnamese court at Huế, if necessary by coercion, that recognised a French protectorate in Tonkin.