WARFARE OF ANTIQUITY. 25 



and triarii ceased, and Caesar formed legions of ten mixed cohorts of four to 

 five hundred men, which he so placed {Jig. 36) that the first line contained 

 four cohorts, and each of the others three. The depth of the cohort, at this 

 time, was ten files. The intervals of the third line were such, that the 

 cohorts of its right and left flanks were exactly in rear of the corresponding 

 cohorts of the first line, while the centre cohort exactly covered that of the 

 second line, and the interval between the second and third was greater than 

 that between the first and second lines. Under Augustus, however, another 

 order of battle was adopted (Jig. 37), the third line being done away with, 

 and the cohorts receiving at the same time a different division. The first 

 consisted of 1,105 foot and 132 horse, and carried the eagle of the legion 

 as well as the image of the emperor ; the remaining cohorts consisted of 

 onlv 555 foot and 66 horse. The first formed, in two divisions, the right 

 wing, and then came the four others, of which the central cohort Q and 

 the flank cohort (^) were composed of the best men. The five following 

 cohorts made the second line ; and of these also the flank and centre cohorts 

 (', ^ and '") were of picked men. The intervals between the cohorts had 

 only half the breadth of their fronts. The princeps of the legion was 

 primipil, and commanded the four centuries of the first half of the first 

 cohort ; the second princeps of the first cohort commanded two centuries of 

 the second half of that cohort. The first and second hastati had each 150 

 men of the second half of the first cohort, and the first triarius commanded 

 the fifth century of the first half of the first cohort. The centuries had, 

 besides this, particular centurions j and there were decurions over every ten 

 men (contubernium). 



Under Trajan the order of battle was again altered, and assumed the 

 disposition shown in pi. 4, Jig. 38, which represents the order of battle 

 of Arrian against the Alani. The archers stood upon two hills on the 

 flanks, and shot over the heads of the heavy armed cohorts in front of them. 

 The legion stood eight files deep, in close order, i. e. three feet to a file ; in 

 the four first ranks, a a, were those who were armed with light lances ; in 

 the four others, b b, those armed with long lances. Afterwards a ninth 

 rank, c c, was added, consisting of Nomadian, Cyrenean, and other archers ; 

 whereupon, after the commencement of the action, the first-named archers 

 also united in a rank, d d, in rear of all, in order to shoot over the heads of 

 the legion. The station for the war-machines is in the line e e, behind the 

 united order of battle ; and the cavalry collected in eight masses, four of 

 which were stationed at //, in rear of the archers, and the others on the 

 two flanks. Were the foe routed, the legion opened and permitted the 

 cavalry, //, to pass through in pursuit. 



Castrametation also is a part of tactics, and pi. 13, Jig. 1, represents a 

 great Roman camp according to Polybius. The Roman camp had the 

 form of a square, and so soon as the place of encampment was designated, 

 a standard was set up at the best and most open spot, and on each of the 

 four sides of this a line of 100 feet was staked ofl*. The square so formed. A, 

 was the prcBtorium, and contained the praetor's tent. In front of this, and 

 on the side most convenient to water and forage, the legions were 



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