Vaasa, or Vasa in Swedish, (Wasa in Latin), is a city on the west coast of Finland. It received its charter in 1606, during the reign of Charles IX of Sweden. It is named after the Royal House of Vasa. Today, Vaasa has a population of 57,266 (2005), and is part of the administrative province of Western Finland and the regional capital of Ostrobothnia. The history of Korsholm (Mustasaari in Finnish) and also of Vaasa begins in the 14th century, when seafarers from the coastal region in central Sweden disembarked at the present Old Vaasa, and the wasteland owners from Finland Proper came to guard their land. In the middle of the century Saint Mary's Church was built and in the 1370's the building of the fortress at Korsholm, Crysseborgh, was undertaken, and served as an administrative centre of the Vasa County. King Charles IX of Sweden founded the town of Mustasaari on October 2, 1606 around the oldest harbour and trade point around the Mustasaari church approximately seven kilometres to the southwest from the present city. In 1611 the town was chartered and renamed after the Royal House of Vasa.