The Sino-French War also known as the Tonkin War and Tonquin War, was a limited conflict fought from August 1884 to April 1885. There was no declaration of war. The Chinese armies performed better than its other nineteenth-century wars and the war ended with French retreat on land and the momentum in China's favour. However lack of foreign support, French naval supremacy, and northern threats posed by Russia and Japan forced China to enter negotiations. China ceded its sphere of influence in Tonkin (northern Vietnam) to France and recognized all the French treaties with Annam turning it into a French protectorate. The war strengthened the dominance of Empress Dowager Cixi over the Chinese government, but brought down the government of Prime Minister Jules Ferry in Paris. Both sides ratified the Treaty of Tientsin.