flee back to Qiao'ao. Xiao considered defending Qiao'ao against the coming Northern Wei assault, but Shen persuaded him that doing so was futile, and despite orders from Emperor Wen to defend Qiao'ao, Xiao led the main forces back to Licheng (歷城, in modern Jinan, Shandong) to preserve the strength of the army. Meanwhile, due to Wang's defeat at Huatai, although the general Liu Wenjing () was able to capture Tong Pass in the west and threaten Northern Wei's Guanzhong region, Emperor Wen chose to recall Liu and abandon the western advances as well. In retaliation for the Liu Song attack, Emperor Taiwu launched an all-out attack against Liu Song's northern provinces. Emperor Taiwu's nephew Tuoba Ren () quickly captured Xuanhu and Xiangcheng (項城, in modern Zhoukou, Henan) and pillaging his way to Shouyang. Emperor Taiwu himself advanced on Pengcheng, but did not put that heavily fortified city under siege; rather, he advanced south, claiming that he would cross the Yangtze River and destroy the Liu Song capital Jiankang. Both his main army and the other branch armies that he sent out carried out heavy slaughters and arsons, laying Liu Song's Huai River region to waste. Around the new year 451, Emperor Taiwu had reached Guabu (瓜步, in modern Nanjing, Jiangsu), across the river from Jiankang, but at this point he reproposed the marriage-peace proposal he made earlier—that if Emperor Wen married a daughter to one of his grandsons, he would be willing to marry a daughter to Emperor Wen's son, Liu Jun (who was then defending Pengcheng), to establish long-term peace. Crown Prince Shao favored the proposal, but Jiang Dan () opposed, and the marital proposal was not accepted. In spring 451, worried that his forces were being overstretched and would be attacked in the rear by the Liu Song forces garrisoned at Pengcheng and Shouyang, Emperor Taiwu began a withdraw, and on the way, insulted by the Liu Song general Zang Zhi (), he put Xuyi (盱眙, in modern Huai'an, Jiangsu) under siege, and, after both sides suffered heavy losses but with the defense holding, quickly withdrew. This campaign appeared to heavily wear out both empires and demonstrated the cruel parts of Emperor Taiwu's personality well, as Sima Guang described it in this manner: Sima Guang further attributed Emperor Wen's military failures to his command style: As another historian, Shen Yue, pointed out, Emperor Wen modelled his military planning