 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.