An attack was begun on the 7th of June, 1099, headed by Godfrey, Tancred, Robert of Normandy, and Robert of Flanders. The barbicans were carried, and a portion of the wall was thrown down; but such was the strength of the fortifications, and so obstinate the defence of the Turks, that it became necessary to construct engines of assault similar to those which had been used in the siege of Nicæa. Catapults and movable towers were prepared, and to these was added a machine called the "sow," made of wood, and covered with raw hides to protect it from fire. The hollow space within was filled with soldiers, who, with this protection, were occupied in undermining the walls. To secure success in the final effort of the enterprise, the leaders exerted themselves to heal the dissensions which had hitherto existed in the army, and Tancred set an example of conciliation by embracing his foe, Raymond of Toulouse, in sight of the troops. An expiatory procession, headed by the chiefs and the clergy, was made round the walls of the city, and prayers were offered up at some of the holy places in the neighbourhood for the success of the Christian arms. These demonstrations were treated by the Turks with contempt. They mocked at the procession as it passed before them, and having raised the Cross upon the walls, they threw dirt upon the sacred symbol. The anger of the Crusaders was excited to the utmost, and their interpretation of the religion of peace permitted them to mingle oaths of vengeance with the prayers for victory. [Illustration: CRUSADERS ON THE MARCH. (_From the Painting by Sir John Gilbert, R.A., P.R.W.S., in the Victoria and Albert Museum._)] The preparations having been completed, the towers were rolled up to the walls, and the attack commenced. The chiefs of the Christian army appeared on the higher stages of the towers, and Godfrey of Bouillon himself was seen with a crossbow in his hand directing his shafts within the town. The Turks replied by pouring out sheets of flame[23] and flights of arrows upon their assailants. The assault had continued for ten days without result, when the Crusaders redoubled their efforts. Some soldiers from the tower of Godfrey effected a lodgment on the walls, and were followed by the Lord of Lorraine, with Baldwin de Bourg, and other chiefs. Robert of Normandy and Tancred forced one of the gates, and the standard of the Cross was raised upon the walls of Jerusalem on the 15th of July, 1099.