On 14 August 1917, China declared war on Germany and recovered the German concessions in Hankow and Tientsin. As a reward for joining the Allies, China was promised the return of other German spheres of influence following the defeat of Germany. However, at the Paris Peace Conference, Japan's claims trumped prior promises to China, and the Treaty of Versailles assigned the modern, up-to-date city of Tsingtao and the Kiautschou Bay region to Japan. The subsequent recognition of that Allied betrayal sparked the nationalistic May Fourth Movement, which is regarded as a significant event in modern Chinese history. As a result, the Beiyang government refused to sign the treaty.