| 摘要: | 劉宋帝國，乃是紛亂的魏晉南北朝時局中，立國於江南的政權，其盛時力抗雄踞於北的胡族國家，地控江南、五嶺，尚曾霸有河南之地，雖然國祚不過僅一甲子的時光，但卻是由盛極一時的門閥政治，漸次轉型向皇權政治的過渡時代，故具承先啟後、繼往開來的時代意義。
中國中古時期之門閥政治，乃萌芽於漢魏，後因永嘉亂起，晉室南渡，由於皇權勢弱，唯賴高門華閥翼戴，方得立國，故呈現士族秉政，而皇帝垂拱之格局，此象徵著皇帝需與士族共治天下。逮至晉末時局，出身寒門的劉裕，本因名微位薄而身處權力邊緣，因緣際會之下，其藉北府軍團資歷、自號著姓彭城劉氏之後，以御武戡亂於晉末時局脫穎而出，突破「上品無寒門，下品無勢族」的門第侷限，權重一時。當時，劉裕成功地整合族群、社會階級、意識形態不相為一的各股勢力，共組政團，代晉自立，建立以「寒門皇帝」為尊的統治秩序。不過，劉裕雖然承運禪代，但一時之間仍未能完全改變政治文化和體制，門閥政治雖終，卻完而不了，遺緒猶存，故其初建霸業伊始，政權即存在不安的因子，終劉裕之世亦未能妥善解決。
繼起之劉宋諸帝，多以年少繼位，故彼等常需面對輔弼重臣挾權用事，以及士族憑藉門資而居權重之任，使君臣之節徒致虛名，諸帝為矯正體制之失，謀求皇權集中，欲以君臣∕兄弟共治天下，建立「皇室家族政治體制」，藉以消弭士族、權臣之干預。見諸史載，諸帝常命天潢貴冑開府置佐，出為都督、刺史，入為宰輔、群公，希冀借助彼等之力掌控軍政要務，休戚與共，擴大皇權基礎，此為「後門閥政治」時代中之重要舉措。但是，皇親國戚因領兵置佐而廣植朋黨，對政治影響力遽增，或有宗王勢傾天下，權亞人主，漸不容於皇帝，是以諸帝始終對彼等心存忌疑，致使統治集團內的各次級團體――「派系」，相互攻訐、紛爭不斷。因此，皇帝與宗王相互依存，卻又對立的兩面性，成為政治角力的根源。
本文逐一檢視從晉宋鼎革至宋齊易代，此時段中重要的政治事件發展始末及其連結，再審視統治集團內，上至皇帝下至諸王群臣，各自集結而成的次級團體――「派系」，用以分析劉宋權力結構的凝聚、變化及其影響，以此觀察其權力核心的建構過程，以及統治集團分合的內在規律，進而理解在「門閥政治」之後，劉宋何以易動難安，權鬥頻仍，終因無休止的內釁而為權臣所乘，日後繼起之齊、梁二朝亦如是般。
The Liu Song Empire was a regime based in the Jiangnan region during the tumultuous Wei-Jin Southern and Northern Dynasties. At the zenith of its power, it stood fast against the barbarian (“Hu”) states to its north, ruled over the Jiangnan and Wuling regions, and dominated the Henan region at one point. Though the regime itself only lasted six decades, the gradual transition away from the rule of aristocratic families to that of imperial rule during those years was of tremendous historical significance.
The aristocratic family system in Medieval China emerged during the Han-Wei period. When the Jin Dynasty fled south due to widespread unrest during the Yongjia Era, the weakness of imperial power meant the support of aristocratic families were necessary for dynastic survival. As a result, the aristocratic families governed while the emperor ruled by laissez-faire. The arrangement represented the sharing of powers between the emperor and the aristocracy. Towards the end of the Jin Dynasty, a commoner named Liu Yu on the peripheries of power saw his opportunity. Drawing on his links with the Beifu Army, he styled himself as Liu of Pengcheng and emerged as a leading force for stability during troubled times. He broke down the old status quo of “no commoners in the upper ranks, and no aristocrats in the lower ranks” and acquired tremendous power. Liu Yu successfully forged the various factions representing different ethnic groups, classes and politics into a single political entity. Together, they founded a new empire in the place of Jin and established a new order with the “Commoner Emperor” at its head. Even though Liu Yu managed to proclaim himself the emperor with the mandate of heaven, he was not able to completely overhaul the political culture and systems. He unseated the aristocratic family system but could not eliminate it altogether. The seeds for future instability were therefore sown at the very start of his rule and continued to be a problem at his death.
Most of the later Liu Song emperors ascended the throne in their youth so they often had to deal with politically powerful ministers, or aristocrats that rose to high positions by virtue of their birth. To avoid this undermining of imperial power, the emperors attempted to centralize imperial authority and share power with their own brothers. The establishment of an “imperial ruling house” sought to eliminate
interference from aristocrats and powerful officials. Historical records documented how the emperors often appointed their kinsmen to important regional posts such as captains or governors, or chancellors and top officials at the imperial court. By working together to maintain control of important military and administrative affairs, the emperors hoped to keep their kinsmen loyal and expand the imperial power base. Such measures were an important feature of “post-aristocracy rule.” On the other hand, imperial kin given military commands and fiefdoms built up their own support base and quickly acquired tremendous political influence. Some princes even began to rival the emperor in their power. The emperors were therefore always suspicious of their kin and this led to constant infighting among different factions within the ruling class. The emperors and imperial princes were therefore dependent on each other but also at loggerheads. The duality of this relationship underpinned their struggles for political ascendancy.
This paper examines the background and implications of important political developments between the transition from the Jin to the Song dynasty, and from the Song to the Chi dynasty. All the “factions” within the ruling class from the emperor down to the princes and top officials are also reviewed to analyze how the power structure of Liu Song took shape, how it changed, and its effects. By observing how the corridors of power coalesced as well as the divisions and alliances within the ruling class itself, we can gain an understanding of why the Liu Song dynasty continued to suffer from instability and power struggles despite the end of the “aristocratic family system.” In the end, the constant infighting allowed powerful officials to usurp the throne, a fate that would later befall the Chi and Liang dynasties as well. |
