The Vikings came to Iceland in the ninth century. There, Europe's oldest representative body was founded, the Althing. About the year 1000, Christianity arrived. First under Norwegian rule (1200s) and then under the Danish (1380), Iceland had to wait until 1918 to gain its independence, although it continued to share a king with Denmark. When the Nazis occupied Denmark during World War II, Iceland declared itself a republic. An early member of the United Nations and NATO, Iceland has no armed forces (the US operated a base at Keflavik). The population of Iceland is one of the world's most educated and healthiest; comprehensive social benefits are available to all thanks to the country's Scandinavian-style welfare state.