The Grand Duke of Luxembourg (Luxembourgish: Groussherzog vu Lëtzebuerg, French: Grand-duc de Luxembourg, German: Großherzog von Luxemburg) is the monarchical head of state of Luxembourg. Luxembourg has been a grand duchy since 15 March 1815, when it was created from territory of the former Duchy of Luxembourg. It was in personal union with the United Kingdom of the Netherlands until 1890 under the House of Orange-Nassau. Luxembourg is the world's only sovereign Grand Duchy and since 1815, there have been nine monarchs, including the incumbent, Henri. From Wikipedia
