In 1568, the Spanish navigator Álvaro de Mendaña was the first European to visit the Solomon Islands archipelago, naming it ''Islas Salomón'' ("Solomon Islands") after the wealthy biblical King Solomon. It is said that they were given this name in the mistaken assumption that they contained great riches, and he believed them to be the Bible-mentioned city of Ophir. During most of the colonial period, the territory's official name was "British Solomon Islands Protectorate" until 1975, when it was changed to "Solomon Islands". The definite article, "the", is not part of the country's official name but is sometimes used, both within and outside the country. Colloquially the islands are referred to simply as "the Solomons".