¹ Domaszewski, A. v., Die Rangordnung des römischen Heeres, 2nd, enlarged ed. by Dobson, B. (Köln, 1967), 90 ff. and xxiii ffGoogle Scholar. For the title of a legion's administrative princeps, both specified and not specified, see CIL viii, 18072Google Scholar, contra: Picard, G.-Ch. and Bonniec, H. Le, ‘Du nombre et des titres des centurions lǵgionnaires sous le haut-empire’, Revue Philologique xi (1937), 112–24Google Scholar. For specified titles of other centurions see Passerini, A., ‘Legio’ in Ruggiero, E. de, Dizionario Epigraphico iv (1950), 549–629, esp. 587 ffGoogle Scholar: also Ensslin, W., Princeps, RE viii (1956), 628–640, esp. p. 628 fGoogle Scholar. This paper was written with the help of a grant by the National Endowment for the Humanities (Research Materials); the views presented here are not necessarily those of the Endowment. I am grateful to Professors Eric Birley and B. Dobson for valuable suggestions.

² CIL viii, 18072Google Scholar; Domaszewski, op. cit. (note 1), 50. According to Domaszewski (l.c. 97) the staff of a provincial governor was also headed by a princeps, assisted by an adiutor.

³ Cohorts: Pap. Dura Europos 89 = Fink, R. O., Roman Military Records on Papyrus (Cleveland, Ohio, 1971), 50Google Scholar, i, 1 and 8; ii, 1 and a, I: ordinatus princeps admissa pronuntiavit (cf. ibid. 51, ii, 6); for a possible decurio princeps in the same cohort see Timinius Paulinus, Fink, op. cit., 47, i, 6 and the possible two principes of CIL iii, 7631Google Scholar; Ann. Epigr. 1968, 436; Dessau 2595 (princeps equitum). Alae: CIL iii, 5938:Google ScholarDEC I AL. Cf. P. Abinn. 10 (A.D. 350). The curious decurio et princeps of an ala (Ann. Epigr. 1915, 69), and the corresponding κɛντυρίων ὁ κα[ι] πρίνκιΨ of a cohort (Inscr. Graec. ad res rotn. pert, i, 894Google Scholar), seem to show that a real function and not just a ranking of officers was involved. Equites singulares Augusti: CIL vi, 31174Google Scholar and Ann. Epigr. 1935, 156: princeps. Very possibly of a part-mounted cohort is CIL iii, 8029Google Scholar = Inscr. Daciae Rom. ii, 338Google Scholar (Romula-Malva, Dacia): Placidae Reginae eq(uites) v(otum) l(ibentes) p(osuerunt) per Proculo princ(ipe) et [G]aio opt(ione).

⁴ CIL iii, 12679Google Scholar (Doclea, Dalmatia): I(ovi) o(ptimo) m(aximo), Epon(a)e Regin(ae), Genio loci, P. Bennius Egregius, mil(es) coh(ortis) vol(untariorum) adiu[t(or)] princ(ipis), b(ene)f(iciarius) co(n)s(ularis) v(otum) s(olvit). Domaszewski, op. cit. (note 1), 34, saw this adiutor as a beneficiarius of the governor, seconded to the provincial headquarters' staff, but the findspot of the monument away from the capital suggests rather that Egregius was first adiutor principis in his cohort's staff, then beneficiarius detached to Doclea. Wilkes, J. J., Dalmatia (London, 1969), 123Google Scholar, rightly assumed stationing as bf. cos. at Doclea. For a likely adiutor pr[in(cipis)] of the equites singulares Augusti see CIL vi, 3196Google Scholar with Domaszewski, op. cit. (note 1), 53, but it is doubtful whether the tabularium numeri of the equites singulares Augusti was the office of their decurio princeps as assumed by Domaszewski, op. cit. (note 1), 50, cf. Speidel, M., Die Equites Singulares Augusti (Bonn, 1965), 35 f.Google Scholar For the administrative function of the auxiliary princeps see also Gilliam, J. F., ‘An Egyptian Cohort in A.D. 117’, Bonner Historia-Augusta-Colloquium 1964/63 (Bonn, 1966), 91–7, esp. 92.Google Scholar

⁵ For the praetorian princeps castrorum see Domaszewski, op. cit. (note 1), 101 and Durry, M., Les cohortes prétoriennes (Paris, 1938), 137Google Scholar f. Dobson, B. and Breeze, D. J., ‘The Rome Cohorts and the Legionary Centurionate’, Epigr. Studien viii (1969), 100–24, esp. 119Google Scholar, reject Domaszewski's identification of the princeps praetorii with the princeps castrorum and, rightly so, at least as far as the further hypotheses are concerned that Domaszewski built on the princeps praetorii. For the nauarchus princeps see Wickert, L., ‘Die Flotte der römischen Kaiserzeit’, Würzburger Jahrbücher iv (1949–1950), 100–25, esp. 115Google Scholar; Kienast, D., Untersuchungen zu den Kriegsflotten der römischen Kaiserzeit (Bonn, 1966), 20 and 40.Google Scholar

⁶ Baillie-Reynolds, P. K., ‘The Troops Quartered in the Castra Peregrinorum’, JRS xiii (1923), 168–89Google Scholar. Dobson, B., Die Primipilares (Köln, 1978), 222Google Scholar, suggests the title became a regular rank, but his inscription no. 265 does not support this.

⁷ The optio was necessary for a commander as his deputy, see Vegetius (2, 7): Optiones ab adoptando appellati, quod antecedentibus aegritudine praepeditis hi tamquam adoptati eorum atque vicarii solent universa curare. See also Festus, 184 M (as quoted by Chilver, G. E. F., A Historical Commentary on Tacitus' Histories I and II (Oxford, 1979), 87)Google Scholar: optio in re militari appellatus is quem decurio aut centurio optat sibi rerum privatarum administrum, quo facilius obeat publica officia.

⁸ CIL xiii, 6623Google Scholar = Dessau 9119. The reading princip(ibus) advocated by Schwertheim, E., Die Denkmäler der orientalischen Gottheiten im römischen Deutschland (Leiden, 1974), 172CrossRefGoogle Scholar, is contradicted by his plate 113; see now also Castritius, H., Manfred Clauss and Leo Hefner, ‘Die römischen Steininschriften des Odenwaldes’ in Wackerfuss, W. (ed.), Beiträge zur Erforschung des Odenwaldes II (Breuberg-Neustadt, 1977), 237–308Google Scholar (but discard the reading agent(es)).

⁹ Ann. Epigr. 1940, 220.

¹⁰ ibid. 1954, 264.

¹¹ ibid. 1937, 239.

¹² CIL ii, 3588Google Scholar = Dessau 5960 in the new reading by Alföldy, G., ‘Eine Inschrift auf dem Montgó bei Dianium an der spanischen Ostküste’, Epigraphica xl (1978), 59–90, esp. 76.Google Scholar

¹³ Ann. Epigr. 1954, 265.

¹⁴ ibid. 1954, 266.

¹⁵ ibid. 1926, 146.

¹⁶ Thus, e.g. Alföldy, op. cit. (note 12), 79; Saxer, R., Untersuchungen zu den Vexillationen des römischen Kaiserheeres von Augustus bis Diokletian (Köln, 1967), 129, n. 665Google Scholar. Gilliam, J. F. in Rostovtzeff, M. I., The Excavations at Dura-Europos IX/III (New Haven, 1952), 112Google Scholar, commenting on our no. 7, suggests that the princeps as chief centurion of his cohort had a regular connection with the cult acts of the unit. Carcopino, J., ‘Le limes de Numidie et sa garde syrienne’, Syria vi (1925), 118–49, p. 42 f.CrossRefGoogle Scholar, wrongly suggests that the princeps of our no. 9 called himself so out of vanity, but he is right to say that one would here expect the title praepositus vexillationis.

¹⁷ The primipilus cited by Saxer, op. cit. (note 16), does not refer to a vexillation, see Saxer's note 450 (p. 80) and for the inscription, Dobson, op. cit. (note 6), no. 210.

¹⁸ The phrase (centurione) princ(ipe) pr(aeposito) ve[x(illationum)] of our no. 2 does not contradict this: the word praepositus here reinforces the word princeps. A certain difficulty is presented by our no. 4, where the princeps is preceded by another, presumably higher officer, whose title, however, is lost; Gilliam, J. F. in Perkins, Ann (ed.), The Excavations at Dura-Europos, Final Report V/I (New Haven, 1959), 26Google Scholar, rightly points out that this officer may not have been present at all at Dura; by contrast Picard-Le Bonniec, op. cit. (note 1), 122, for no good reasons see in him a princeps praetorii. Likewise, the title princeps cohortis (no. 8) does not imply that the entire cohort (rather than a detachment) was present at Dura, for detachments are frequently given the name of their parent units without indication that they are only detachments, cf. Ritterling, E., ‘Legio’, Pauly-Wissowa, Realencyclopädie xii (1924), 1221–829Google Scholar (for the time of M. Aurelius) and RIB 1147, 1148 (A.D. 139).

¹⁹ Actarii and librarii went along with detachments on expeditions, cf. Ann. Epigr. 1934, 279. During the Later Roman Empire every camp had its princeps.

²⁰ For comparison see the table 3 in Breeze, D. J. and Dobson, B., Hadrian's Wall (Harmondsworth, 1978), 48.Google Scholar For a description of the fort, Bruce, J. Collingwood, Handbook to the Roman Wall, 13th ed. by Daniels, C. (Newcastle, 1978), 228 ff.Google Scholar

²¹ Birley, E., Research on Hadrian's Wall (Kendal, 1961), 138 f.Google Scholar

²² Davies, R. W., ‘A Note on a Recently Discovered Inscription from Carrawburgh’, Epigraphische Studien iv (Köln, 1967), 108–11.Google ScholarBirley, E., ‘A Note on the Second Cohort of Tungrians’, Trans. Cumbd. Westmd. Antiq. Arch. Soc. n.s. xxxv (1935), 56–60.Google Scholar Idem, ‘Raetien, Britannien und das römische Meer,’ Bayerische Vorgeschichtsblätter 45 (1980), 77–89 esp. p. 82.

²³ The reading q(uorum) c(uram) a(git) is due to Professor John Mann, as Professor E. Birley tells me. I do not consider the O in the middle of Maurorum to be missing: the drawing in RIB shows it there, only shrunk to almost a point.

²⁴ On Ain Wif see Goodchild, R. G. and Ward-Perkins, J. B., ‘The Limes Tripolitanus in the Light of Recent Discoveries’, JRS xxxix (1949), 81–95.Google Scholar The inscription ibid. and Inscr. Rom. Tripolitania 868.

²⁵ R. Saxer, op. cit. (note 16), 101, no. 300, wrongly understands Thenadassa to be a castellum. Devijver, H., Prospographia Militarium Equestrium (Leuven, 1976Google Scholar), no. C 76, is right in assuming that Caninius held both commands at the same time.

²⁸ Goodchild – Ward Perkins, op. cit. (note 24); Inscr. Rom. Tripolitania 869.

²⁷ Devijver, op. cit. (note 25), no. C., 216. The princeps as commander of the vexillation: Goodchild – Ward Perkins, op. cit. (note 24), 88; Saxer, op. cit. (note 16).

²⁸ The sixth British inscription mentioning an auxiliary princeps yields little for our study (RIB 792): I(ovi) O(ptimo) M(aximo), Genio loci, Subr(ius) Apollinaris, princep(s) c(ohortis) I V[––––]. It is tempting to see a p(rinceps)d(ecurio) v(exillationis) in RIB 1421: Matrib(us) templ(um) cum ara vex(illatio) coh(ortis) I Vard(ullorum) instante PDV, v(otum) s(olvit) l(ibens) m(erito): unfortunately, the mention of an officer's rank without his name is just as odd as if PDV were his name without a rank.

²⁹ See the examples discussed above. Another case is more difficult to assess: the Greek equivalent of princeps pro(ector––) primip(il–––) of Inscr. Graec. Bulg. iii 2, 1570Google Scholar has been expanded by Domaszewski (above, note 1), 188, as princeps prot(ectorum), primip(ilaris) with the explanation that the man was princeps of a collegium of protectores like other alleged principes of their collegia. Yet the existence of principes as heads of collegia is doubtful (see the following note). Hence Inscr. Graec. Bulg. iii 2, 1570Google Scholar may mean a princeps as an ad hoc commander of the numerus primipilarium that accompanied the emperor on campaigns (‘Hyginus’, 6) – read princeps prot(ector) primip(ilarium), unless one takes the title princeps prot(ector) to denote a titulary legionary princeps, for which see Christol, M., ‘La carrière de Traianus Mucianus et l'origine des protectores’, Chiron vii (1977), 393–408.Google Scholar

³⁰ Yet another military use of the word princeps occurs in the ranking of NCO's, where one finds a princeps signifer, signifer secundus, etc. (CIL viii, 4333Google Scholar; Pap. Dura Europos 89, i, 2 = Fink, op. cit. (note 3), 50, cf. ibid. 184 ff.); for a possible p(rinceps) d(uplicarius) leg(ionis) I Ital(icae) see Kazarov, G., Die Denkmäler des thrakischen Reitergottes in Bulgarien (Budapest, 1938), 112Google Scholar, no. 599, with photograph. A tubicen princ. has recently come to light (Bull. Arch. Algérienne v (1976), 11)Google Scholar and perhaps a bucinator principalis (Ann. Epigr. 1896, 21) also belongs to this group. Such principes, however, are not the heads of collegia as surmised by Domaszewski (preceding note): Ann. Epigr. 1907, 184 shows an optio in that position, above the pr(inceps) of the tubicines. An unpublished inscription from Kotiaion, Asia, mentions a princeps optio: π[ρίνκɛΨ] ὀπτίων that might refer to the senior optio, cf. Th. Drew-Bear, Les voyages d'Aurelius Gaius, Soldat de Diocle'tien, forthcoming. In such cases the word princeps apparently expresses seniority rather than rank.

³¹ Princeps may even have been the title of the commander of local constables at Smyrna, for in the Acta of Pionius 15 the ίππαρχοσ μɛτὰ διωγμιτῶν says, apparently of himself, Άλλὰ πρίνκιΨ ἐστὶν ἀξιόγοσ, see Musurillo, H., The Acts of the Christian Martyrs (Oxford, 1972), 156 f.Google Scholar, with the unconvincing translation ‘An imperial officer is worthy of respect!’ Perhaps princeps means here ‘local commander’.