The Franks colonized the area around Nordhausen about 800, many place names here have a Frankish origin, discernible by the suffix "-hausen" (like Nordhausen itself, Sundhausen, Windehausen and the later abandoned settlement Stockhausen as well as the neighbouring cities of Mühlhausen, Sondershausen, Frankenhausen and Sangerhausen). Nordhausen itself is first mentioned in a 13 May 927 document of King Henry the Fowler. He built a castle here, which is traceable between 910 and 1277 and became a centre of the empire during the 10th century. Gerberga of Saxony, Henry's daughter is supposed to have been born there, as was Henry I, Duke of Bavaria. The first market was established in the 10th century, as was a chapter of nuns (961). During the 12th century, the "old town" was semi-planned and established around the new market place and St. Nicholas' Church.