<論説>元首政期ローマ帝国における近衛長官職の確立

Abstract

元首政期ローマ帝国において、本来極めてわずかな軍事権限しかもち得なかった近衛長官職は、徐々に国政における役割を増やしていき、三世紀の軍人皇帝時代には、国政運営の様々な面において指導的役割を果たすようになった。そればかりか、帝位を纂奪する近衛長官さえしばしば出現したのである。先行研究ではこのような近衛長官隆盛の基はセウェルス朝期に築かれたとし、特に法学者パピニアヌスらが連続して近衛長官職に就いたことが近衛長官職の内政的側面の発達の画期であると理解し、重視してきた。しかし、本稿における検討の結果、法学者近衛長官の意義は低いものであり、近衛長官職発展の画期は、従来軽視されてきた五賢帝期後期であったことが明らかになった。この時代に、近衛長官職は権限・地位が上昇して職務として確立したのである。騎士身分を中心とする三世紀半ばの政治体制へと元首政が移行していく基盤は、五賢帝期後期に成立したといえよう。

At the beginning of the Principate the praefectus praetorio (praetorian prefect) was merely a minor office. By the mid-third century, however the powers of the praetorian prefect had expanded to encompass both military and civil aspects of state administration. Indeed, during this period, the praetorian prefect was so powerful as to be known as "vice-emperor". Scholars have generally asserted that such powerful praetorian prefect arose during the Severan Period. To them, the pattern by which the praetorian prefect became entrusted with civil powers was best exemplified by the appointment of the great jurists Papinian and Ulpian as praetorian prefects(jurist-prefects). According to this view jurist-prefects were the most powerful men in government. Closer scrutiny reveals however that the powers of these jurist-prefects have been vastly overrated, because each was dually appointed and held rank inferior to the other(non-jurist) prefect. In other words, the role of jurist-prefects was less significant than ever indicated. I believe that both the military and civil powers of the praetorian prefect expanded most markedly during the Antonine period. In addition to securing significant civil powers, the praetorian prefect played a greater role in warfare as well. Furthermore, many prefects were bestowed the ornamenta consularia, which led to a dramatic increase in the authority of that office. Indeed, the status of the prefect became equal to that of a senator or more than that. In other words, it was the Antonine period which witnessed the development of the praetorian prefect into a significant post. During this same period, a system of equestrian office also became highly developed. The increase in the powers and status of the praetorian prefect coincided with the development of the equestrian order, with the praetorian prefect being officially admitted as its highest officer. Because the framework for the rise of this equestrian order in the third century was already extant in the Antonine Period, it is during that age that one can posit the beginnings of the transition to the later Roman Empire.