Aju and Liu Zheng arrived in 1268 and blockaded the city with a ring of
forts. Liu Zheng had advised the cities be starved from Sichuan by building forts there. The Mongols probed the defenses of
Xiangyang and
Fancheng. The Yuan-Mongols learned from their mistake, and this time brought along with them about a hundred
trebuchets. These trebuchets had a shooting range of around 100 metres, and could use projectiles of around 50 kg. During Mongol campaigns against the
Jin dynasty, the Mongols used about 5,000 trebuchets, and they were very successful in destroying the Jin fortresses. Lu Wende commanded the Song dynasty's Yangtze and his son-in-law Fan Wenhu and son Lu Wenhuan commanded Xiangyang. However the twin cities had expected an assault by bombardment and prepared for it. The city moat was expanded to a width of 150 metres, forcing Yuan siege weapons to set up at a distance. In addition to reinforcing their walls with clay, they made netting screens ten centimetres thick and ten metres in length to cover them and dampen projectile impact. As a result, the Yuan siege weapons were both ineffective and inaccurate, and the few shots that did land bounced off the wall harmlessly.
Mongol entrapment The Mongols then started to block Xiangyang off from the rest of Song. A Yuan fleet of 5,000 ships was established, to stop any Song supplies from the Han river. The Han River was blockaded with five stone platforms capped by
arbalests. The Mongol trained 70,000
marines but Song food supplies still held out in 1271. The Yuan also sent forces to go around the fortress, and set up camps at the key roads, to stop Song supplies from land. Eventually, Yuan built their own forts at these key locations. From late 1267 to 1271, Song reinforcements from the south tried, many times, to attack the Mongol positions, in order to supply Xiangyang, but outside of Xiangyang, the Song forces were no match for the Mongolian cavalry. The catalog of useless thrusts continued, the Chinese losing 1,000 in October 1270, 2,000 in August 1271, and most of a 3,000 strong force was destroyed the following month. Once the Yuan forts were completed, the situation became hopeless. As a result, the Song forces inside Xiangyang had to depend on themselves. The Song had stored years of supplies within Xiangyang. However, by 1271, the fortress finally ran low on their supplies. Still, the Song troops chose to hang on. Finally, in 1272, a small Song force of 3,000 men was able to break through the Yuan naval blockade, and supplied Xiangyang from the Han river. The force, led by two men both named Zhang, commanded a hundred paddle wheel boats, travelling by night under the light of lantern fire, was discovered early on by a Mongol commander. When the Song fleet arrived near the cities, they found the Mongol fleet to have spread themselves out along the entire width of the Yangtze with "vessels spread out, filling the entire surface of the river, and there was no gap for them to enter." Another defensive measure the Mongols had taken was the construction of a chain, which stretched across the water. The two fleets engaged in combat and the Song opened fire with fire-lances, fire-bombs, and crossbows. A large number of men died trying to cut through chains, pull up stakes, and hurl bombs, while Song marines fought hand to hand using large axes, and according to the Mongol record, "on their ships they were up to the ankles in blood." With the rise of dawn, the Song vessels made it to the city walls and the citizens "leapt up a hundred times in joy." This was a major morale boost to the defenders. However, no one could get back out to inform others of the success. The Song officials considered that reinforcement lost and Xiangyang, doomed to fall from the lack of supplies, did not send more Song reinforcements afterwards. The high casualties and low success rates ended the transportation of further supplies. Fancheng, after holding out for years, suddenly fell within a few days. The Yuan Mongol army then turned their attention to Xiangyang. Lu Wenhuan sent a messenger to
Emperor Duzong of Song, to request immediate reinforcements. The messenger successfully got by the Yuan forts and reached the emperor. But upon hearing the effectiveness of these new trebuchets, the emperor considered Xiangyang lost and did not send reinforcements. For the next few days, Song soldiers looked to the south for reinforcements, but all they saw were Yuan siege weapons and the Mongols waiting to end their lives. The position of Song forces worsened when, in February, Yuan siege weapons began bombarding the city. A shot happened to hit a stone bridge inside the city. When the stone landed, it made a thunderous noise. Song soldiers went to check the damage, and saw that the stone had sunk a few feet into the solid ground. The Yuan bombardment began to collapse the city structures as well as reduce the drum tower and turrets on the city walls. Lu Wenhuan surrendered the city on 14 March 1273; he was made governor of Xiangyang and Fancheng under Yuan rule as part of the terms. == Aftermath ==