Napoleon spent a night in Beaumont, from 14 to 15 June 1815, 4 days before the battle of Waterloo. He stayed in the old château des Caraman-Chimay on the Grand-Place. Napoleon enjoyed the hospitality of a very powerful and family famous for being the heirs to the Principality of Chimay since 1804. The building probably stands on the site of an old medieval fortress from the 11th century. It was fully converted in a neo-gothic style between 1805 and 1845. Since 1937, when it was bought by the sœurs de Paridaens, the building has housed the Institut Trinité Notre-Dame.
The Northern French army, which was approximately 120.000 strong, had set up camp in a space of 35 by 9 km. Each soldier had enough food for four days and a stewardship service accompanied the army. It was indeed necessary to assure the favour of the civilian population that had been French, by avoiding marauding by French soldier.