A region named Germania inhabited by several Germanic peoples has been known and documented before 100 AD. Since the 10th century German territories have formed a central part of the Holy Roman Empire that lasted until 1806. During the 16th century, northern Germany became the centre of the Protestant Reformation. As a modern nation-state, the country was first unified amidst the Franco-Prussian War in 1871. After World War II, Germany was divided into two separate states along the lines of allied occupation in 1949. The two states became reunified again in 1990. West Germany was a founding member of the European Community (EC) in 1957, which became the European Union in 1993. It is part of the borderless Schengen zone and adopted the European currency, the euro, in 1999.