The name of Waterloo was mentioned for the first time in 1102 designating a small hamlet at the limit of a big forest (Sonian Forest) along a major road linking Brussels and Genappe, and further south the coal mines area. Waterloo was located at the crossing of the main road with a path leading to a farm (cense in Walloon). The crossing still exists : chauss�e de Bruxelles with Boulevard de la Cense. Waterloo was a place where travellers and carriers of goods (mainly coal) could rest and escape the bandits at night.
Waterloo was located in the Duchy of Brabant created in 1183 with Leuven (B) as the capital city. The Duchy of Brabant was extending from Luttre (B) till 's-Hertogenbosch (NL) in 1477. Brussels became the capital city of the Duchy of Brabant in 1267 and the capital city of the Burgundian Netherlands in 1430.
Waterloo started to develop during the 17th century. A royal chapel was built in 1687 in Petit-Waterloo. This chapel still exists and was extended in 1826 at the back to form today's main church of Waterloo.
Because of the new ideas following the French Revolution in 1789, the Holy Roman Emperor (who was governing present day Belgian territories) wanted to impose reforms. This was followed by a period of unrest that ended with the French invasion in 1794. The old regime (rights of the seigniors, the power of the monasteries, the church keeping official registers) was abolished.
Until 1796, Waterloo was divided into two parts (Grand-Waterloo and Petit-Waterloo) depending, respectively, of the parishes of Braine-l'Alleud (Bishopric of Namur) and of Sint-Genesius-Rode (Bishopric of Mechelen).
A new system based on municipalities was established in 1796. The municipality of Waterloo was created from Petit-Waterloo detached from Sint-Genesius-Rode and 3 former hamlets (Grand-Waterloo, Joli-Bois, Mont-Saint-Jean) detached from Braine-l�Alleud. In 1813, half of the hamlet of Chenois
