[38] This organization cannot have taken place earlier since it is obvious from Caesar’s narrative that during the Gallic campaigns no attempt was made to reduce the tribal contingents to units of a fixed size.
[39] Caesar, Bell. Gall. i. 18.
[40] [Caesar,] Bell. Gall. viii. 12. He is described as principe civitatis, praefecto equitum.
[41] Caesar, Bell. Civ. iii. 59.
[42] See Eph. Ep. v. 142, n. 1. The ala is only known from x. 6011.
[43] The alae Flaviana, Petriana, Proculeiana, Tauriana, and Sebosiana all bear ‘Gallorum’ as a secondary title, and the alae Agrippiana, Longiniana, Picentiana, Pomponiana, and Rusonis seem to have been recruited in Gaul in the first century. The Gallic origin of the ala Atectorigiana is even more obvious. The ala Gallorum Indiana may possibly have a later origin, cf. Tac. Ann. iii. 42. The theory given above as to the origin of these regiments is unhesitatingly affirmed by von Domaszewski (Rangordnung, pp. 122, 123), but a little more evidence would certainly be advantageous.
[44] Cf. v. 3366, x. 6309.
[46] Von Domaszewski, in his edition, puts the treatise De munitione castrorum into the reign of Trajan. It is difficult to regard the evidence as decisive, but there can be little doubt that the information contained in the work is in any case applicable to the period under discussion.
[47] Hyginus, 16. An Egyptian inscription, iii. 6581, also gives sixteen as the number of decurions in an ala.