In the Middle Ages Bouillon was a lordship within the Duchy of Lower Lorraine and the principal seat of the Ardennes-Bouillon dynasty in the 10th and 11th century. In the 11th century they dominated the area, and held the ducal title along with many other titles in the region. Bouillon was the location of the ducal mint and the dominant urban concentration in the dukes' possession. The Semois river and the Bouillon Castle (13th/19th centuries)
The fortification of Bouillon Castle was, along with the County of Verdun, the core of the possessions of the Ardennes-Bouillon dynasty, and their combined territory was a complex mixture of fiefs, allodial land and other hereditary rights throughout the area. An example of the latter is the Advocacy of the monastery of Saint-Hubert en Ardennes, which was granted to Godfrey II by the Bishop of Liège.
The most famous of the Lords of Bouillon was Godfrey of Bouillon, a leader of the First Crusade and the first ruler of the Kingdom of Jerusalem. He sold Bouillon Castle to the Bishopric of Liège. The bishops started to call themselves dukes of Bouillon, and the town emerged as the capital of a sovereign duchy by 1678, when it was captured from the bishopric by the French army and given to the La Tour d'Auvergne family. The duchy was prized for its strategic location as "the key to the Ardennes" (as Vauban called it) and hence to France itself. It remained a quasi-independent protectorate, like Orange and Monaco, until 1795, when the Republican Army annexed it to France.
After the defeat of Napoleon Bonaparte, the city was given to the Netherlands in the 1815 Treaty of Paris. It has been part of Belgium since the Revolution of 1830.
The E46 runs by Bouillon making it easily accessible by car. There is sufficient free parking in the town.
The town is connected with the Wallonia TEC bus network. Bus 8 connects train stations Libramont and Beatrix (bus stop in town centre) to Bouillon every 2 hours.
The town is small enough to explore by foot.
A small tourist train also connects the main sights