The next year, William decided to extend his father's hunting residence to a palace which met his new status. This would later be called the Binnenhof ("Inner Court") and was the beginning of the city of The Hague. Meanwhile, after a siege of five months, William besieged Aachen for six months before capturing it from Frederick's followers. Only then could he be crowned as king by Archbishop Konrad of Cologne. He gained a certain amount of theoretical support from some of the German princes after his marriage to Elizabeth, daughter of the Welf duke Otto of Brunswick-Lüneburg, on 25 January 1252. He was elected as King of the Romans a second time on 25 March 1252 at Brunswick. The electors were the Archbishops of Cologne, Mainz and Trier, the Margrave of Brandenburg and the Duke of Saxony. The Count Palatine, who was also Duke of Bavaria, was excluded from taking part in the election on the ground that, as a supporter of Conrad IV, he was under sentence of excommunication. After the election, the King of Bohemia sent ambassadors conveying his consent to it. However, although "William lacked neither courage nor chivalrous qualities... his power never extended beyond the Rhineland."