In 522, Emperor Wu's nephew Xiao Zhengde—whom he had previously adopted but then unadopted when Xiao Tong was born—resentful that he was not created crown prince, fled to Northern Wei, claiming to be the deposed crown prince and requesting Northern Wei aid. However, Northern Wei did not take his claim seriously, and in 523 Xiao Zhengde fled back to Liang. Instead of punishing Xiao Zhengde, however, Emperor Wu merely rebuked him tearfully, and in fact restored him to his title of Marquess of Xifeng. In winter 523, with his state plagued by forgeries of its copper coins, Emperor Wu abolished copper coins and started minting iron coins. (The actual fiscal impact of this act was unclear, but traditional Chinese historians generally considered iron to be unsuitable to use for coinage.) In 524, Emperor Wu launched a number of attacks on Northern Wei's southern territory, with Northern Wei forces occupied with fighting agrarian rebellions to the north and west. Liang forces largely met little resistance. Further, in spring 525, the Northern Wei general Yuan Faseng () surrendered the key city of Pengcheng (, in modern
Xuzhou,
Jiangsu) to Liang. However, in summer 525, Emperor Wu's son Xiao Zong (), who suspected that he was actually the son of Southern Qi's emperor Xiao Baojuan (because his mother Consort Wu was formerly Xiao Baojuan's concubine and had given birth to him only seven months after she became Emperor Wu's concubine), in turn surrendered Pengcheng to Northern Wei, ending Liang's advances in the northeast, although in summer 526, Shouyang fell to Liang troops after Emperor Wu successfully reemployed the damming strategy. For the next several years, Liang continued to make minor gains on the borders with Northern Wei. Over the years, Emperor Wu had increasingly given additional authorities to Xiao Tong the Crown Prince, and the relationship between father and son was dear. However, in 526, after the death of Xiao Tong's mother Consort Ding Lingguang (), the relationship would deteriorate. Xiao Tong sought out an appropriate place to bury Consort Ding, but while he was doing so, a land owner bribed the
eunuch Yu Sanfu () into convincing Emperor Wu that that piece of land would bring good fortune for the emperor, and so Emperor Wu bought the land and buried Consort Ding there. However, once Consort Ding was buried, a
Taoist monk informed Xiao Tong that he believed that the land would bring ill fortune for Consort Ding's oldest son—Xiao Tong. Xiao Tong therefore allowed the monk to bury a few items intended to dissolve the ill fortune, such as wax ducks, at the position reserved for the oldest son. Later on, when one of Xiao Tong's attendants, Bao Miaozhi (), was squeezed out of Xiao Tong's inner circles by another attendant, Wei Ya (), he, in resentment, reported to Emperor Wu that Wei had carried out sorcery on Xiao Tong's behalf. When Emperor Wu investigated, waxed ducks were found, and Emperor Wu became surprised and angry, and wanted to investigate further. He only stopped the investigation when he was advised to do so by the prime minister
Xu Mian, executing only the Taoist monk who had suggested the burial of wax ducks. Xiao Tong became humiliated in the affair, and was never able to clear himself completely in his father's eyes. In 527, Emperor Wu made his first offering of himself to the service of Buddha (,
sheshen) at Tongtai Monastery (), spending three days there. In 528, after a coup in Northern Wei, with the warlord
Erzhu Rong overthrowing
Empress Dowager Hu (after she killed her own son,
Emperor Xiaoming of Northern Wei, with poison), a number of Northern Wei officials, including Yuan Yue () the Prince of Ru'nan, Yuan Yu () the Prince of Linhuai, and
Yuan Hao the Prince of Beihai, fled to Liang, and a number of other officials surrendered territories they controlled to Liang. In winter 528, Emperor Wu created Yuan Hao the Prince of Wei—intending to have him lay claim to the Northern Wei throne and, if successful, become a Liang vassal—and commissioned his general
Chen Qingzhi with an army to escort Yuan Hao back to Northern Wei. Despite the small size of Chen's army, he won battle after battle, and in spring 529, after Chen captured Suiyang (, in modern
Shangqiu,
Henan), Yuan Hao, with Emperor Wu's approval, proclaimed himself the emperor of Northern Wei. In summer 529, with Northern Wei troops unable to stand up to Chen,
Emperor Xiaozhuang of Northern Wei fled the Northern Wei capital
Luoyang, and Yuan Hao took it. However, Yuan Hao secretly wanted to rebel against Liang, and when Chen requested Emperor Wu to send reinforcements, Yuan Hao sent Emperor Wu a submission advising against it, and Emperor Wu, believing Yuan Hao, did not send additional troops. Soon, Erzhu Rong and Emperor Xiaozhuang counterattacked, and Luoyang fell. Yuan Hao fled and was killed in flight, and Chen's own army was destroyed, although Chen himself was able to flee back to Liang. Emperor Wu, realizing the impossibility of the task he gave Chen, nevertheless created Chen the Marquess of Yongxing in recognition of his victories. In fall 529, Emperor Wu made his second offering of himself to the service of Buddha at Tongtai Monastery—but contrary to the first time he did, when he simply spent three days at the monastery, he stripped himself of imperial clothing and wore those of monks, and spent all day carrying out monastic tasks, including daily chores and giving of lectures on the
Nirvana Sutra. He spent 12 days at the monastery, and returned to the palace only after the imperial offices made a huge donation to it—formally, to ransom "the Emperor
Bodhisattva." In 530, Emperor Wu made another attempt to establish a vassal regime in Northern Wei—by creating Yuan Yue the Prince of Wei, and commissioning Yuan Yue's uncle Fan Zun () with an army to escort Yuan Yue back to Northern Wei. Yuan Yue made some advances, particularly in light of the disturbance precipitated soon thereafter when Emperor Xiaozhuang ambushed and killed Erzhu Rong and was in turn overthrown by Erzhu Rong's nephew
Erzhu Zhao and cousin
Erzhu Shilong. However, Yuan Yue realized that the Erzhus then became firmly in control of Luoyang and that he would be unable to defeat them, and so returned to Liang in winter 530.
Xiao Tong's Death In 531, Xiao Tong who was the Crown Prince at the time died, and Emperor Wu personally attended his wake and buried him in a tomb appropriate for an emperor. He also summoned Xiao Tong's oldest son, Xiao Huan () the Duke of Huarong back to the capital Jiankang, preparing to create Xiao Huan crown prince to replace his father, as would be appropriate under
Confucian principles of succession. However, still resentful over the wax duck affair, he hesitated for days without carrying out the creation, and finally did not do so. Instead, against popular opinion, he created Xiao Tong's younger brother, also by Consort Ding,
Xiao Gang crown prince. To compensate Xiao Tong's three sons, he created the princes of large commandery—Xiao Huan the Prince of Yuzhang, Xiao Yu () the Prince of Hedong, and
Xiao Cha the Prince of Yueyang, but his grandsons continued to resent him. In 532, with Northern Wei again in civil war after the general
Gao Huan rose against the Erzhus, Emperor Wu again sent an army to escort Yuan Yue back to Northern Wei, and subsequently, Gao Huan welcomed Yuan Yue, but then decided against making Yuan Yue emperor. Subsequently,
Emperor Xiaowu of Northern Wei, whom Gao made emperor, had Yuan Yue executed. In 534, with Mars seen in the
Dipper constellation—traditionally thought to be a sign that the emperor would be forced to leave the palace—Emperor Wu tried to divert the ill fortune by walking barefoot around his palace. However, he soon heard that Northern Wei's Emperor Xiaowu had fled Luoyang in a dispute with Gao splitting Northern Wei into two separate countries. Wu, both glad and embarrassed, stated, "Is it that even barbarians correspond to astrological signs?" ==Late reign==