Liu Jun 劉駿, Emperor Xiaowu of the Song Dynasty 宋孝武帝

Emperor Xiaowu 宋孝武皇帝 (r. 453-464), personal name Liu Jun 劉駿 (430-464), courtesy name Xiulong 休龍, childhood name Daoren 道人, was the third son of Emperor Wen 宋文帝 (r. 424-453) and the fifth ruler of the Liu-Song dynasty 劉宋 (420-479), one of the Southern Dynasties 劉宋 (420-479). His mother was Lady Lu 路淑媛 (see female offices). He was a young man interested in military skills. In 453, he was invested as Prince of Wuling 武陵. In 445, he was appointed regional inspector (cishi 刺史) of the province of Yongzhou 雍州, and in 451 transferred to Jiangzhou 江州, where he also took over the function of Commander-in-Chief (dudu 都督).

In 453, Liu Jun's older brother Liu Shao 劉劭 (424-453) killed their father and usurped the throne. Within a few months, Liu Jun revolted against his brother, killed him, and seized the imperial throne himself. He chose the reign motto Xiaojian 孝建.

His reign was characterised by deep mistrust towards the high officials and his relatives. Liu Jun appointed document clerks (dianqian 典簽), who had the duty to assist and spy out his brothers and cousins. This measure led to deep resentment in the dynastic house. Moreover, he deprived the princes of certain ceremonial and entertaining privileges, like chariots, insignia or orchestras. In the course of these conflicts, his younger brothers Liu Shuo 劉鑠 (431-453), the Prince of Nanping 南平王, Liu Hui 劉渾 (439-455), the Prince of Wuchang 武昌王, Liu Xiumao 劉休茂 (445-461), the Prince of Hailing 海陵王, and Liu Dan 劉誕 (433-459), the Prince of Jingling 竟陵王, were killed. After the suppression of Liu Dan's rebellion, Liu Jun ordered to massacre the male inhabitants of Guangling 廣陵城, and give all women as slaves to his army.

In order to accommodate the northern exile people (qiaoren 僑人; see qiaozhou 僑州), Liu Jun carried out a land reform in the province of Yongzhou 雍州 and consolidated exile commanderies (qiaojun 僑郡), shifting the refugee settlers to regular household registers. He also interdicted the uncontrolled land acquisition in mountain and swamp regions, which had hitherto led to large tracts of land not being registered and taxed. Attempts to reduce the number of tax-exempted monks and nuns failed because the clergy was too influential at the court.

Liu Jun died in 464. He is buried in the tomb hill Jingning 景寧陵 (close to Nanjing 南京, Jiangsu). His posthumous title is Emperor Xiaowu, and his temple name Shizu 宋世祖. He was succeeded by his oldest son, Liu Ziye 劉子業, the First Deposed Emperor 宋前廢帝 (r. 464-465).