In 1568, Spanish navigator Álvaro de Mendaña became the first European to sail through the archipelago, sighting the island of Nui during an expedition he was making in search of Terra Australis. The island of Funafuti was named Ellice's Island in 1819. Later, after the work of English hydrographer Alexander George Findlay, the name Ellice began to be applied to the whole nine-island group. In the late 19th century, Great Britain claimed control over the Ellice Islands, designating them as within their sphere of influence as the result of a treaty between Great Britain and Germany that demarcated their respective spheres of influence in the Pacific Ocean. Between 9 and 16 October 1892, Captain Gibson of  declared each of the Ellice Islands to be a British protectorate. Britain assigned a resident commissioner to administer the Ellice Islands as part of the British Western Pacific Territories (BWPT). From 1916 to 1975, they were managed as part of the Gilbert and Ellice Islands colony.