[151] The number of legions existing at this date is not absolutely certain, but it seems most probable that there were twenty-eight. Cf. von Domaszewski in the _Römisch-germanisches Korrespondenzblatt_, 1910, on the date of the creation of legions XXI and XXII. [152] Tac. _Hist._ ii. 58. [153] Josephus, _Bell. Iud._ iii. 4. 66. Twenty-three cohorts (of which ten, an unusually high proportion, were _miliariae_) and six alae, of unspecified size. That the auxilia had been very largely drawn on is shown by the fact that Titus in 70, although he had a whole additional legion and detachments from two others, had only twenty cohorts and eight alae; Tac. _Hist._ v. i. [154] Tac. _Hist._ iii. 2. The garrison of Noricum is probably not included. [155] This is on the supposition that the auxilia would have been drawn upon in the same proportion as the legions. Some of the regiments which remained behind seem to have been very much weakened, others such as the Ala Picentiana and the Ala Batavorum probably remained fairly intact. Tac. _Hist._ ii. 89, iv. 15, 18, 62. Vitellius may have had some of the British auxilia with him (cf. Tac. _Hist._ ii. 100, iii. 41), but these are more than counterbalanced by the eight Batavian cohorts which had been sent back. [156] For the provenance of these regiments, particularly the large levies made by Trajan in the Eastern provinces, see the following section. [157] On the other hand, Legio IX Hispana, destroyed in Britain at the beginning of the reign, and XXII Deiotariana, which was probably annihilated in Judaea either at the same date or twenty years later, were not replaced until Marcus raised legions II and III Italica for the defence of Noricum and Raetia. SECTION II RECRUITING AND DISTRIBUTION In making a levy for the auxiliary regiments, the imperial government was under no obligation to be at pains to legalize its position. In an ancient state it was assumed, as a matter of course, that the government had the power to call upon every citizen, if need arose, to take his place in the fighting line. Even the privileged _cives Romani_ were never freed under the Empire from the legal obligation to military service, however much they may have been spared in practice, so that there can have been little doubt about the position of _peregrini_. Only in the case of the _civitates foederatae_ was the government theoretically required to limit its demands to the number of men stipulated in the original _foedus_.