The Czech Republic is a nation state in Central Europe bordered by Germany to the west, Austria to the south, Slovakia to the east and Poland to the northeast. The Czech Republic covers an area of 78,866 square kilometres with mostly temperate continental climate and oceanic climate. It is a unitary parliamentary republic, has 10.5 million inhabitants and the capital and largest city is Prague, with over 1.2 million residents. The Czech Republic includes its historical territories of Bohemia, Moravia, and Czech Silesia. The Czech state was formed in the late 9th century as the Duchy of Bohemia under the Great Moravian Empire. After the fall of the Empire in 907, the centre of power transferred from Moravia to Bohemia under the Přemyslid dynasty. In 1004, the duchy was formally recognized as part of the Holy Roman Empire, becoming the Kingdom of Bohemia in 1198 and reaching its greatest territorial extent in the 14th century. Besides Bohemia itself, the king of Bohemia ruled the lands of the Bohemian Crown, he had a vote in the election of the Holy Roman Emperor, and Prague was the imperial seat in periods between the 14th and 17th century. In the Hussite wars of the 15th century driven by the Bohemian Reformation, the kingdom faced economic embargoes and defeated five crusades proclaimed by the leaders of the Roman Catholic Church.