Duke of Brabant
The title was created by the Holy Roman Emperor Frederick Barbarossa in favor of Henry I of the House of Reginar, son of Godfrey III of Leuven (who was duke of Lower Lorraine at that time).Although the corresponding county was quite small (limited to the territory between the rivers Senne and Dender) its name was applied to the entire country under control of the dukes from the 13th century on.Later on, it followed with the Burgundian inheritance until the French Revolution, although the northern part of the territory of Brabant was actually governed by the United Provinces during the 17th and 18th centuries (see Generality Lands).Today, the title of duke or duchess of Brabant designates, since the Royal Decree of 16 December 1840 (amended in 1991), the heir apparent to the throne of Belgium.The oldest son or daughter automatically becomes the duke/duchess of Brabant when his/her father becomes King of the Belgians; there is no ceremony or formal oath that the new duke/duchess must pass.