The Sung fortunes showed some slight symptoms of improving when Kiassetao was disgraced, and a more competent general was found in the person of Chang Chikia. But the Mongols never abated the vigor of their attack or relaxed in their efforts to cut off all possibility of succor from the Sung capital. When Chang Chikia hoped to improve the position of his side by resuming the offensive he was destined to rude disappointment. Making an attack on the strong position of the Mongols at Nankin he was repulsed with heavy loss. The Sung fleet was almost annihilated and 700 war-junks were taken by the victors. After this the Chinese never dared to face the Mongols again on the water. This victory was due to the courage and capacity of Artchu. Bayan now returned from a campaign in Mongolia to resume the chief conduct of the war, and he signalized his return by the capture of Changchow. At this town he is said to have sanctioned a massacre of the Chinese troops, but the facts are enwrapped in uncertainty; and Marco Polo declares that this was only done after the Chinese had treacherously cut up the Mongol garrison. Alarmed by the fall of Changchow, the Sung ministers again sued for peace, sending an imploring letter to this effect: "Our ruler is young and cannot be held responsible for the differences that have arisen between the peoples. Kiassetao the guilty one has been punished; give us peace and we shall be better friends in the future." Bayan's reply was severe and uncompromising. "The age of your prince has nothing to do with the question between us. The war must go on to its legitimate end. Further argument is useless." The defenses of the Sung capital were by this time removed, and the unfortunate upholders of that dynasty had no option save to come to terms with the Mongols. Marco Polo describes Kincsay as the most opulent city of the world, but it was in no position to stand a siege. The empress-regent, acting for her son, sent in her submission to Bayan, and agreed to proceed to the court of the conqueror. She abdicated for herself and family all the pretensions of their rank, and she accepted the favors of the Mongol with due humility, saying, "The Son of Heaven (thus giving Kublai the correct imperial style) grants you the favor of sparing your life; it is just to thank him for it and to pay him homage." Bayan made a triumphal entry into the city, while the Emperor Kongtsong was sent off to Pekin. The majority of the Sung courtiers and soldiers came to terms with Bayan, but a few of the more desperate or faithful endeavored to uphold the Sung cause in Southern China under the general, Chang Chikia. Two of the Sung princes were supported by this commander, and one was proclaimed by the empty title of emperor. Capricious fortune rallied to their side for a brief space, and some of the Mongol detachments which had advanced too far or with undue precipitancy were cut up and destroyed.