Norway has a long history dating back 9,000 years, and was united as a kingdom in 900 AD. It gained independence from Sweden in 1905 after 400 years of union. Norway celebrates its national day on May 17th, characterized by children's parades wearing traditional costumes. Norway has a unique monarchy established by referendum in 1905. It is a founding member of the UN and NATO but has rejected joining the EU. Norway has a mixed economy relying on oil and gas exports, and offers virtually free public higher education through universities and colleges.