The town of Goslar emerged from one of these settlements on the northern edge of the Harz Mountains, founded in AD 922 in the reign of Henry I of East Francia (Henry the Fowler), according to Saxon tradition. The first written record, for Otto II, does not appear until 979. In 934, it is likely that a royal castle was built on the hill of the Georgenberg and, from 968, the mining industry at Rammelsberg was developed. The mineworkers need for this industry lived in Bergedorf around the church of St. John. The embossed silver Otto Adelheid pennies made of Goslar silver are the first tangible evidence of the mining industry. The onset of metallurgy around 990 required professional tradesmen who were distinguished from the native Saxons as Franks and settled on the so-called Frankenberg.