Tatihou Island extends in the harbor of Saint-Vaast-la-Hougue, in the Cotentin peninsula of the Manche department. The site was occupied by the army until the First World War. From 1910, civilian prisoners stayed on the island under the surveillance of the military. During World War I, the fort housed German and Austro-Hungarian war prisoners. In 1939, Fort de Tatihou welcomed refugees of the Retirada during the Spanish Civil War.