Principality of Brunswick-Wolfenbüttel
A Saxon noble "Alardus" of Burgdorf is mentioned as a witness, when in 1218 Emperor Otto IV made his will at nearby Harzburg Castle. Alardus' ancestors had been vested with estates around the former Werla "Kaiserpfalz" in the 12th century and probably erected the castle where the Ecker River formed the border of the County of Wernigerode with the Principality of Brunswick-Wolfenbüttel.