The city was laid out at the behest of the Ascanian rulers, their successor Margrave Louis I from the Bavarian House of Wittelsbach even established a monastery of the Servite Order in 1335, which was dissolved during the Protestant Reformation. Altlandsberg was devastated by the Hussites in 1432, it was affected by several town fires and plague epidemics in the 16th century. The medieval town was burnt down completely in 1632 during the Thirty Years' War. A hoard of 7450 gold and silver coins dating from the 14th and early 15th century was discovered in the grounds of the former manor in late 2016. The dates suggest that it was buried in order to protect it during the Hussite wars. It is the largest hitherto found in the state of Brandenburg, and is now being examined in the archeological museum in Brandenburg an der Havel.