In the second half of the 11th century, a village was founded at the location where the Thumeritz brook empties into the Thaya river. The counts of Pernegg established a parish there in 1100. With that began also the settlement of the nearby hill above the church with its surrounding village. Thus a new castle town was formed. The castle wall was erected 1.5 meters thick and 8 meters high. Two gates led into the city.
Drosendorf thus became one of the fortified towns along the border with Bohemia, like Raabs or Hardegg. In 1240 Drosendorf was declared a city. In 1278 its hour of glory struck, when the city was defended under the command of Stephan von Maissau for sixteen days against the onslaught of the Bohemian army of Ottokar II. In that way King Rudolf of Habsburg won time to amass his forces for a successful battle against Bohemia in Marchfeld. Out of gratitude Drosendorf was elevated to the level of an imperial city. In the 15th century when the Hussite Wars were raging, the capacity of firepower also increased. Thus the city wall needed to be further fortified to a thickness of 2 meters and a height of 10 meters. Additionally zwingers were built, including embrasures (loopholes in the fortification for firing weapons). During the Thirty Years War the Swedish army marched right past, without taking any action; presumably the walls instilled too much awe in them.
Today it stands as the only completely enclosed city wall in Austria and is under heritage protection. It offers excellent views to the meandering Thaya river. City tours provide interesting insights into its eventful history.