 He was possibly a son of Gilbert, Duke of Lorraine, and his mother Cunigunda was a granddaughter of the West Frankish King Louis the Stammerer.In the following years, Siegfried built a new castle on the site of the ruins, on a rock later called "Bockfiels".The castle dominated a stretch of the old Roman road linking Reims, Arlon and Trier that provided prospects for trade and taxation.