Bohuslän (ˈbûːhʉːsˌlɛːn; Bohuslen; Båhuslen) is a Swedish province in Götaland, on the northernmost part of the country's west coast. It is bordered by Dalsland to the northeast, Västergötland to the southeast, the Skagerrak arm of the North Sea to the west, and the county of Østfold, in Norway, to the north. In English it literally means Bohus County, although it shared counties with the city of Gothenburg prior to the 1998 county merger and thus was not an administrative unit in its own right. Bohuslän is named after the medieval Norwegian castle of Bohus. Under the name Baahuslen, it was a Norwegian county from the Norwegian conquest of the region from the Geats and subsequent unification of the country in the 870s until the Treaty of Roskilde in 1658, when the union of Denmark–Norway was forced to cede this county, as well as Skåneland (part of Denmark proper), to Sweden. the number of inhabitants was 299,087, giving a population density of . The provinces of Sweden serve no administrative function. Instead, that function is served by the counties of Sweden. For centuries, the administrative county for Bohuslän was Gothenburg and Bohus County, and as its name implies it consisted of the entire Bohuslän province together with the city Gothenburg. In 1998, some Swedish counties were merged to reduce administration costs, and Gothenburg and Bohus County were therefore merged into the new, much larger Västra Götaland County. Bohuslän was granted its arms at the time of the funeral for Charles X Gustav of Sweden in 1660. It was identical to the arms of the Town of Kungälv. In 1962 the higher claim of the town was established and a variation for the arms of the county was introduced. The coat of arms is surmounted by a ducal coronet. Blazon: 'Argent, a Castle embattled Gules with one embattled Tower of the same and two doors Or hinged Sable between a Sword point upwards and Lion rampant holding the Tower both Azure langued and armed Or." The geography is distinguished by the rocky coast, bordering an archipelago: there are about 3,000 islands and 5,000 islets (skerries).