漢制與胡風：重探北魏的「皇后」、「皇太后」制度

Rethinking the Institutions of “Empress” and “Empress-Mother” in the Northern Wei

關於北魏皇后、皇太后制度如何在華夏制度與鮮卑習俗的交匯中發展變化，以及其與國家體制的關係，至今仍有許多研究上的空白。本文重新檢討北魏自道武帝到孝明帝之間「皇后」、「皇太后」制度具體實踐發展的狀況，思考鮮卑拓跋氏所根植的北亞部族文化可能帶來的影響，嘗試透過儒家禮制與拓跋鮮卑婚姻、繼承等習俗之比較，澄清並說明北魏「皇后」、「皇太后」制度的內涵與特質。在孝文帝推行更深層的漢化之前，北魏皇后、皇太后的產生方式及職分權力、皇帝與皇太后的關係定位、皇后與皇太后位號是否相連遞升等面向，皆深受北亞文化影響，與華夏制度差異極大。孝文帝時期對皇后制度的改造，可視作其漢化改革的一環，至此確立北魏皇后作為「嫡妻」的地位與政治權威，是北魏皇后、皇太后制度的重要轉折點。中古女主頻出，北魏曾有兩位乳保出身的皇太后預政，以及文明太后、胡太后兩位太后臨朝攝政。本文仔細檢討這些太后取得位分的基礎、參預政治的權力來源、權力的表現形式與侷限，以及太后在國家體制中的地位。發現北魏皇太后的權力來源並非來自嫡妻身分，而是母親身分，其統治性質並非只是輔佐幼帝、暫時代理皇權，而是以「皇帝之母」的身分與皇帝共同治理天下。北魏以「母子共治」為核心形成的「二聖」並尊統治型態，以及「皇帝之母」與神聖地位、政治權力的連結，打破皇帝一人獨尊格局，展現女主政治的另類型態；其所創造的政治文化遺產也為後來一代女皇武曌所汲引援用。

This article reexamines the development of the Northern Wei institutions of “empress” and “empress-mother” between the reigns of Emperor Daowu (r. 386-409) and Emperor Xiaoming (r. 515-528). The article clarifies the characteristics of these institutions by assessing the influence of Northern Asian culture on the Northern Wei and highlighting the contrasts between the Confucian ritual system and the marriage and succession customs of the Tuoba. Before Emperor Xiaowen (r. 471-499) began to intensify the sinicization of the Northern Wei, the establishment of empresses and empress-mothers, the powers of these positions, the relationship between emperors and empress-mothers, and the connection between the positions of empress and empress-mother were all deeply influenced by Northern Asian culture, and differed greatly from the Chinese system. The changes Emperor Xiaowen made to the institution of empress were a key turning point, associating the authority of a Northern Wei empress with her status as a “wife” in the Chinese ritual system. Female rulers were not uncommon in medieval China. In the Northern Wei, for instance, there were two emperor’s wet nurses who became empress-mothers and were involved in politics, and two empress-mothers who ruled the entire country. From a careful examination of how these empress-mothers rose to power, the sources of their political authority, how their authority was expressed (and limited), and the place of the empress-mother within the political system as a whole, this article shows that the authority of a Northern Wei empress-mother came not from being the former emperor’s wife but from being the mother (or wet nurse) of the current emperor. She was not merely acting as a temporary regent for a young emperor, but ruling together with him in her capacity as “the mother of the emperor.” In the Northern Wei, the idea of the emperor as the sole sovereign ruler gave way to a system in which “two sages,” the emperor and his mother, held power together. The political and cultural heritage of the institution of the empress-mother would later become one of the resources used by Wu Zhao (r. 683-705) to found China’s only female emperorship.