ab tergo, i.e. by Hannibal’s cavalry and the Gauls.
18-19 non illa . . . triarios = not in that well-known (illa) mode of fighting (sc. pugna) arranged according to. . . . Livy refers to the old mode of formation (said to have been introduced by Camillus) of i. hastati, of young men, ii. principes, of men at their prime, iii. triarii, of middle-aged men.
References: Polybius, iii. 82-84; Ihne, Hist. vol, i. pp. 204-10.
SECOND PUNIC WAR, 218-202 B.C.
The Battle of Lake Trasimene, 217 B.C. (3)
The Death of Flaminius.
Dumque ea commemorat densosque obit obvius hostes,
Advolat ora ferus mentemque Ducarius. Acri
Nomen erat gentile viro, fusisque catervis
Boiorum quondam patriis, antiqua gerebat