著者

井上 文則

出版者

日本西洋古典学会

雑誌

西洋古典学研究 (ISSN:04479114)

巻号頁・発行日

vol.52, pp.84-94, 2004

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In 1903 E Ritterling put forward a new theory the emperor Gallienus created four independent cavalry corps, all under the control of one commander Aureolus This theory was developed by A Alfoldi who used coins as a historical source to argue that these four independent cavalry corps were converted into the central cavalry corps stationed at Milan Alfoldi's argument was generally accepted However, H G Simon recently rebutted it and denied the existence of such corps on the grounds that the main Greek sources concerning Gallienus' reform of cavalry are unreliable In this paper, I examine Gallienus' supposed reform of cavalry to clarify the military system of the Roman Empire in the mid-third century First, I attempt to reconstruct the career of Aureolus who is key to understanding cavalry reform According to the Greek sources, Aureolus was commander of the central cavalry corps at the time of his rebellion against Gallienus But there are many inconsistencies in the Greek sources and further the Latin historian Aurelius Victor said that Aureolus was commanding the army in Raetia when he revolted In Simon's view, the Latin source is more reliable and he reinterprets the Greek sources to reconcile them with the Latin source Since his interpretation seems unconvincing, I here propose another solution to this problem I argue that Aureolus was the commander of the central cavalry corps at the time of Gallienus' war against Postumus in 265, not in 268 and that after concluding the war Aureolus remained in Raetia to defend the invasion of Postumus into Italy I observe that there is no evidence for the existence of the central cavalry corps except the title of Aureolus Rather it is recognized that independent cavalry corps, such as the Dalmatian cavalry corps, played a prominent part in many battles Moreover there were some independent cavalry corps not included into the central cavalry corps, though it is commonly said that they are all created to form it Form these observations, I suggest that Gallienus originally intended to create the independent cavalry corps and the central cavalry corps was temporarily formed from the independent cavalry corps which happened to be under the direct command of the emperor To understand the real significance of the independent cavalry corps, it is necessary to consider to the phenomenon that prior to the cavalry reform, Roman legion, which mainly consisted of infantry, divided into the vexillatio for independent use By creating a new cavalry unit corresponding with vexillatio, Gallienus probably intended to form mobile field forces, containing both cavalry and infantry I can find it not only under the direct command of the emperor but also deployed by other military commanders elsewhere It seems probable that such military condition in the mid-third century shaped Diocletian's later policy to divide the Roman Empire into four parts