The Duke William had conferred upon his guests the spurs of knighthood, and he proposed that, in order to enable them to display their prowess, they should accompany him on an expedition into Brittany. As long as the war lasted, Harold and William lived under a single tent and dined at the same table. On one occasion, after the Saxons had distinguished themselves by their warlike feats, the two chiefs were returning home together on horseback. William was speaking of his old relations with King Edward. "When Edward and I lived like brothers, under the same roof," he said, "he promised me, that if ever he should become king of England, he would make me heir to his kingdom. Harold, help me to get this promise fulfilled. If by your help I should obtain the kingdom, rest assured that whatever you ask for, I will immediately grant." Harold, astounded, did not know what to answer. He stammered a few words. William was resolved to get his consent. "Since you consent to serve me, you must undertake to fortify Dover Castle," he said, "to construct a well there for obtaining a supply of spring water, and to surrender it up to my soldiers. You must give up your sister to me, whom I will give in marriage to one of my barons; and you shall marry my daughter Adela. I also wish that, when you go, you would leave one of the two hostages whom you have claimed; I will take him back to England when I go over there as king." Harold shuddered inwardly. He was at the duke's mercy, and he agreed to all that he desired, mentally resolving not to fulfil his promises. He did not know the Norman and his farsighted schemes. {87} They were at Avranches (some say at Bayeux), and the Norman barons were convoked in a great assembly. The Saxon was there by the side of the duke; a massbook was brought and placed upon a stool covered with a golden cloth. Suddenly William exclaimed, "Harold, I call upon you, before this noble assembly, to confirm on oath all that you have promised to do to help me to obtain the kingdom of England after the death of King Edward." The Englishman was again taken aback, and was in great peril. He advanced slowly, and swore with his hand on the book, to perform the promises made to the duke, provided that he were alive and that God should help him to do so. All the Normans cried out, "May the Lord help him!" Then at a sign from William, the rich cloth was removed and the Saxon discovered that he had sworn upon a receptacle filled with precious relics which had been brought, by order of the duke, from all the neighboring convents. William did not detain Harold any longer. He left the country, taking his nephew with him; but his brother remained in the power of the Normans. "Did I not warn you that I knew William?" said the old king Edward when Harold related to him what had happened; and he added sadly, "May none of these misfortunes happen in my lifetime!"