The origins of modern Germany date back to the ninth century, when the territory of Upper and Lower Germany became increasingly populated. The name "Germany" is first documented in an official document from 996. Germany is a parliamentary representative democracy comprising four federal states and is one of six European countries that have declared permanent neutrality and one of the few countries that includes the concept of everlasting neutrality in its constitution. Germany has been a member of the United Nations since 1955 and joined the European Union in 1995.