關於北魏太武帝的毀廢佛法，前此學者的研究大都環繞在國家的政策、宗教上的佛道之爭、思想上的儒釋之辨等方面來討論。本文嘗試著從一個比較大的背景來思考這個事件。 由於太武滅佛的引爆點是公元四四五年杏城盧水胡人蓋吳的反叛，不過，學者都沒有特別注意到在陝西起兵的蓋吳是盧水胡人，而盧水胡人是篤信佛教的，並且從這個角度來探討蓋吳反叛和滅佛的關連。從五世紀初以來，北魏和盧水胡政權的北涼有相當的互動關係，並且在公元四三九年攻下北涼的都城姑臧，把北涼王室和臣民三萬餘家遷到平城。不過，北涼國主的兩個弟弟卻遠走高昌，在那裡延續北涼的政權；而被遷到平城的王室成員也有人起來反叛。此外，從五世紀以來盧水胡人或是直接、或是間接控制著北魏和南朝通往西域的道路。以上各項因素的盤結交錯，終於促成了太武帝的滅佛。 本文第二節首先討論五世紀上半葉華北、西北的政治地理，其中特別著重盧水胡的敘述，包括盧水胡的來源及其遷移，盧水胡的居住地區、以及其和西域、南朝的交通。第三節探討蓋吳的反叛。第四節討論蓋吳反叛中潛藏的滅佛宗教因素。第五節敘述太武帝的滅佛事件，以及滅佛之後一連串誅殺在平城的沮渠王族，實為滅佛的後續行動，足以顯示出太武滅佛的背後實含有其對盧水胡族的猜疑。

　　　　　Previous scholarship about the suppression of Buddhism during the fifth century by the Northern Wei 北魏 emperor Taiwudi 太武帝 (r. 435-452) has focused on the dynasty’s political history, the on-going struggle between Buddhism and Taoism, and even the tensions between Buddhism and Confucianism. In this paper, I attempt to approach this topic from a new and different perspective: one that takes into account the problems of ethnicity and religion in north China during the medieval era. Although the event that sparked Taiwudi’s suppression campaign was an uprising in 445 led by Gai Wu 蓋吳, a member of the Lushui 盧水 branch of the Xiongnu 匈奴 people, few scholars have taken into account the on-going antagonism between the Xiongnu and the Tuoba 拓跋 branch of the Xianbei 鮮卑 people, which ruled much of north China as the Northern Wei dynasty. In addition, the fact that Gai Wu and other Lushui people were devout Buddhists may have contributed to Taiwudi's antipathy towards that religion. Even before Gai Wu's rebellion, Taiwudi had fought against the Lushui people in 439 during his campaign against the Northern Liang 北涼 dynasty, which ardently supported Buddhism. Following the Northern Wei victory, over 30,000 supporters of the Northern Liang were forcibly resettled in the area around the capital city of Pingcheng 平城 (today's Datong 大同), but two younger brothers of the Northern Liang ruler fled to Gaochang 高昌 (in today's Xinjiang 新疆), where they continued to resist the Northern Wei while also controlling many of the key routes between China and Central Asia. Thus, it is clear that the Lushui people were bitter enemies of the Northern Wei, and a constant thorn in Taiwudi's side. These historical factors, combined with the scale of Gai Wu’s rebellion and his people’s devotion to Buddhsim, all contributed to Taiwudi's campaign of suppression against the Buddhist religion. This paper begins with a description of the geopolitical environment of north China during the first half of the fifth century, with special attention being devoted to the origins of the Lushui people, their migration to north China, and their links to both Central Asia and the Southern Dynasties 南朝. This is followed by a description of Gai Wu's rebellion. The next section of the paper concerns the links between Gai Wu's rebellion and Taiwudi's suppression of Buddhism, while the final section treats Taiwudi's attempts to exterminate those ethnic groups that opposed him both during and after the suppression of Buddhism.