Adomainname.ws – Germany is a federal parliamentary republic in western-central Europe consisting of 16 constituent states, which retain limited sovereignty. Its capital city and largest city is Berlin. Germany covers an area of 357,021 square kilometres (137,847 sq mi) and has a largely temperate seasonal climate. With 80.6 million inhabitants, it is the most populous member state in the European Union. Germany is a major economic and political power of the European continent and a historic leader in many cultural, theoretical and technical fields. Various Germanic tribes have occupied what is now northern Germany and southern Scandinavia since classical antiquity. A region named Germania was documented by the Romans before AD 100. During the Migration Period that coincided with the decline of the Roman Empire, the Germanic tribes expanded southward and established kingdoms throughout much of Europe. Beginning in the 10th century, German territories formed a central part of the Holy Roman Empire.