William of Aubigny and his comrades did hold out, but at desperate odds. Every possible mode of attack--mining, battery, assault--was tried in turn upon the fortress. Five great slinging engines were plied incessantly, day and night, against its walls. The garrison, already short of food, and expecting no mercy from the king if they surrendered, were minded to sell their lives dearly; they fought like heroes; “nor,” says the Barnwell annalist, “does living memory recall any siege so urgently carried on and so manfully resisted.”[1121] A strange contrivance at last shattered the mighty keep. On November 25 John ordered the justiciar to send him with all possible speed “forty bacon-pigs of the fattest, and of those which are least good for eating, to be put to set fire to the stuff that we have got together under the tower.”[1122] Of the results of the blaze thus kindled a token remains to this day, in the round tower which at the south-west angle of the keep contrasts so markedly with the square towers at the other corners, and which replaces the original square one thus destroyed by John. Even after its fall the garrison fought on until their last morsel of food was gone; then at last they surrendered on S. Andrew’s Day.[1123] The king set up a gallows in front of the army and declared he would hang them all; but he yielded to Savaric de Mauléon’s warning that if he hanged brave knights such as these, the barons would surely do the like to any friends of his who might fall into their hands, and that in view of such a prospect no man would remain in his service.[1124] On this he contented himself with sending the knights to prison, leaving the men-at-arms to ransom themselves as best they could, and hanging only a few cross-bowmen.[1125] Three times since the siege began the barons in London, or some of them, had opened negotiations with the king. On October 17 Richard of Argentan and others had a safe-conduct “to treat with us for peace between ourself and our barons”;[1126] on October 22 Roger de Jarpeville and Robert de Coleville had a safe-conduct till the 27th to treat with the king concerning peace between him and “the barons who may come with the Master of the Temple and the Prior of the Hospital”;[1127] and on November 9 a safe-conduct till the 12th was given to Earl Richard of Clare, Robert Fitz-Walter, Geoffrey de Say, and the mayor and two, three or four citizens of London, that they might go and speak with the bishop of Winchester, the earls of Warenne and Arundel, and Hubert de Burgh, “to treat of peace between ourself and our barons.”[1128] On the side of the barons these overtures were nothing but a cloak for the cowardice and incapacity which kept them from taking any active steps for the relief of their besieged comrades. They were all the while pushing on negotiations for bringing in a foreign power to aid them in their selfish scheme of revolution.