The name Alsdorf was mentioned for the first time in a document of the Catholic Church in the year 1191. But it might be much older than 800 years. During its history, Alsdorf changed its affiliation a few times. Along with the duchy of Brabant and the duchy of Limburg, it also belonged to the duchy of Burgundy (1430) and fell to the Habsburgs in 1482. Then in 1555, it became part of the Spanish Netherlands under the Spanish Habsburgs. In 1714, it belonged again to Austrian Habsburgs until the French invasion. After that, pursuant to a judgement of the Congress of Vienna, Alsdorf belonged to Prussia.