在共和國時期之前羅馬名義上的軍事首腦為國王,在共和國建立後改由元老院為名義上的負責單位,在改革時期有羅馬的政治家呼籲軍隊由公民管轄但是沒有成功,最後反而是由出名的統帥掌管:蓋烏斯·尤利烏斯·凱撒,他自封為最高統帥(拉丁語:Imperator,意思是指揮官)以及「國父」(Father of the Country),最重要的是他被賦予「隨意指揮」(could do as he liked)的特權[4]。奧古斯都前31年贏得內戰後,就設置常備職業化軍隊,達28個軍團、三十六萬人[5][6],而羅馬皇帝成為羅馬的統帥(de facto)掌管羅馬的全部軍隊。
軍事文化
歷史學者彼得·希瑟描述羅馬的軍事文化為:「就像是一支古代的皇家陸戰隊,但是卻十分齷齪」[7]。但是在共和國時期軍隊儘管常常倉促訓練後就派遣防守,部隊提倡的團結和道德(esprit de corps)可以結合為有效的作戰力量,爾後的帝國時期雖然軍人戰鬥力強,然而士氣卻往往低落而無戰力可言。[8]
^Estimates range wildly because census data was imprecise and there is some disagreement over how many federated tribes had settled permanently in Roman lands during the Mid to latte Empire.
^Heather, P., The Fall of the Roman Empire, MacMillan, 2005, p. 6
^Heather, P., The Fall of the Roman Empire, MacMillan, 2005, p.6
^Heather, P., The Fall of the Roman Empire, MacMillan, 2005, p. 64
^Caesar is said to have spent "huge portions of the wealth he accumulated in his victorious wars... on celebrating Triumphs... [and] on erecting magnificent buildings". Grant, p. 194
^ 15.015.1Hadas, M, et al., Imperial Rome, in Great Ages of man: A History of the World's Cultures, New York, Time-Life Books, 1965
^Jones, AHM, The Later Roman Empire 284-602, Johns Hopkins University Press, 1964, p.1035
^Edward Gibbon relates that "the fertile... province of Campania...was within sixty years of the death of Constantine... granted an exemption from tax amounting to three hundred and fifty thousand... acres of desert and uncultivated land" - Gibbon, p. 376
^ 18.018.1Santosuosso A., Soldiers, Emperors and Citizens in the Roman Empire, Westview, 2001, p. 214
^Grant, M., The History of Rome, Fabre and Faber, 1993, p. 287
^Heather, P., The Fall of the Roman Empire, MacMillian, 2005, p. 29
^Luttwak notes that Roman troops could march roughly 15 miles per day over long distances, while ships could carry them far more economically and at speeds of 27-81 miles per day. - Luttwak, p. 81
^Heather, P., The Fall of the Roman Empire, MacMillan, 2005, p. 55
^Heather, P., The Fall of the Roman Empire, MacMillan, 2005, p. 7
^Fan Ye, Xiyu chuan ("Chapter on the Western Regions"), in Hou Han shu (Official history of the Later Han Dynasty), ch. 88.