Norway Officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, the Arctic archipelago of Svalbard and the subantarctic Bouvet Island. Norway has a total area of 385,252 square kilometres (148,747 sq mi) and a population of about 5 million. It is the second least densely populated country in Europe. The majority of the country shares a border to the east with Sweden; its northernmost region is bordered by Finland to the south and Russia to the east; in its south Norway borders the Skagerrak Strait across from Denmark. The capital city of Norway is Oslo. Norway's extensive coastline, facing the North Atlantic Ocean and the Barents Sea, is home to its famous fjords.
Two centuries of Viking raids tapered off following the adoption of Christianity by King Olav Tryggvason in 994. A period of civil war ended in the 13th century when Norway expanded its control overseas to parts of the British Isles, Iceland, and Greenland. Norwegian territorial power peaked in 1265, but competition from the Hanseatic League and the spread of the Black Death weakened the country. In 1380, Norway was absorbed into a union with Denmark that lasted more than four centuries. In 1814, Norwegians resisted the cession of their country to Sweden and adopted a new constitution. Sweden then invaded Norway but agreed to let Norway keep its constitution in return for accepting the union under a Swedish king. Rising nationalism throughout the 19th century led to a 1905 referendum granting Norway independence. Although Norway remained neutral in World War I, it suffered heavy losses to its shipping. Norway proclaimed its neutrality at the outset of World War II, but was nonetheless occupied for five years by the Third Reich. In 1949, neutrality was abandoned and Norway became a founding member of NATO. Discovery of oil and gas in adjacent waters in the late 1960s boosted Norway's