Luxembourg is a parliamentary representative democracy with a constitutional monarchy, ruled by a Grand Duke. It is the world's only sovereign Grand Duchy. Luxembourg is a founding member of the European Union, NATO, the United Nations, Benelux, and the Western European Union, reflecting the political consensus in favour of economic, political, and military integration. The city of Luxembourg, the capital and largest city, is the seat of several institutions and agencies of the European Union. Luxembourg lies on the cultural divide between Romance Europe and Germanic Europe, borrowing customs from each of the distinct traditions. While French and Luxembourgish are the predominant languages in daily life and on the streets, Luxembourg remains a trilingual country; French, German, and Luxembourgish are official languages. Although a secular state, Luxembourg is predominantly Roman Catholic.