adventus A formal imperial entry into a city, far more frequent than a triumphal entry and procession (triumphus).
askesis Discipline, more particularly acts that demonstrate one’s commitment to a cause, also the root of the term ‘ascetic’. Bishops, like ‘holy men’ and monks, were expected to perform acts of askesis to consolidate their spiritual authority.
Augustus The title reserved for the senior emperor or emperors (pl. Augusti), distinguished from their junior partners, Caesars.
catechumen A Christian convert under instruction prior to baptism. It was not regular practice to baptize infants, and not all were accepted as catechumens.
centuria The century, the basic unit of the Roman army, comprising eighty men (and not, as one might guess, one hundred men). It was made up of contubernia (tent groups, sing. contubernium) of eight to ten men.
chi-rho A Christogram, or sign of Christ, formed from the two Greek letters that begin his name, chi (X) and rho (P).
cohort A unit of the Roman army. The traditional strength of the cohort was six centuries (of eighty), with the first century being double strength; actual numbers varied between units.
comes Literally ‘companion’ (pl. comites). When used on coins, it might refer to one who consorted with the gods, and later was used to refer to the emperor’s closest companions and advisers, becoming an elevated rank and taking on the meaning of ‘count’.
comitatus Originally meaning ‘retinue’, a group assigned to the person of the emperor. It came to mean a personal bodyguard and later a larger expeditionary force (the comitatenses), to be distinguished from those stationed in garrisons at the frontiers (ripenses).
consul Once the highest elected office for a senator in the Roman republic, this honorific position was entirely in the gift of the emperor. The ordinary consuls gave their names to the year in the Roman calendar, and hence to be appointed consul was a great and distinctive honour.
cursus publicus The official Roman courier service and postal system, which stretched across the whole empire, delivering official messages and transporting officials from station to station.
damnatio memoriae The destruction of memory and legacy that took place when an enemy was defeated or a rival killed. The deceased’s actions and achievements were erased from the historical record, his or her name excised from inscriptions, and his or her existence ignored in future orations and narratives.
divus A minor divinity, usually a deified emperor (feminine, diva, although this is less common; pl. divi), distinct from the gods of the pantheon, each of which was a deus.
felicitas The divine gift of good fortune, most often manifested by victory, given as a reward for imperial virtus.
feriale A calendar prescribing rituals and ceremonies to be performed on certain days by state officers and, notably, those in the army. A version of an army calendar, the Feriale Duranum, has survived.
genius The guardian spirit of almost anything, whether animate (a military unit) or inanimate (a grain store), the genius was commonly portrayed as a nude young man, frequently holding a cornucopia.
henotheism Adherence to a particular god out of several, generally a ‘greatest god’, who might preside over other, lesser deities. Distinct from monotheism, which professed a single god.
invictus Unconquered, or unconquerable, this epithet was accorded to the Sun god, Sol, but also to emperors.
labarum An imperial standard topped with the chi-rho, manufactured by Constantine to be used as a palladium, or protective device, during battle; also, a channel for divine grace, later used as the imperial sceptre.
magister May be translated as ‘master’ as in the case of the magister peditum (Master of the Foot), magister equitum (Master of the Horse) and magister officiorum (Master of Offices, head of the palatine administration, the emperor’s chief-of-staff).
numen A spirit or divine quality. The numen (pl. numina) of the emperor or emperors was venerated rather than the mortal man.
obverse The front of a coin (‘heads’), on which the portrait of an emperor appeared, allowing a variety of designs on the reverse.
panegyric A speech delivered in praise of someone, most often an emperor.
princeps The first or leading citizen, later translated as ‘prince’. It is used in the construction princeps iuventutis, ‘prince of the youth’, a title of Republican origin, once used to identify the leading boy in the Game of Troy. It later passed to the chief of the equestrian order, but under the principate came to be used to designate the scion of the imperial house who was designated to succeed. Often written princeps iuventatis, but one should distinguish between iuventas (gen. iuventatis), which describes the condition of early manhood, and iuventus (gen. iuventutis), meaning more exactly ‘young men collectively’, the latter having a military tone.
quadriga A chariot drawn by four horses, employed in processions and associated in iconography with the Sun god, Sol Invictus.
quaestor Among the highest offices within the palatine administration, the quaestor was the emperor’s principal private secretary and held the rank of comes.
quinquennalia Five-year anniversary celebrations, celebrated with great ceremony, including processions, orations and public prayers (vota). Coins were issued and distributed as gifts (donatives), principally to the army. Similar, still more splendid celebrations marked each successive five years, especially the ten-year (decennalia), twenty-year (vicennalia) and thirty-year (tricennalia) anniversaries.
religio The collection of cult practices and rituals that supported the Roman state and, particularly, imperial enterprises. ‘Religion’ is not a particularly accurate translation into English.
rosaliae Rose festivals, dates in the feriale which for the army became associated with veneration of the standards (signa).
sacramentum An oath, but here particularly the solemn oath sworn by soldiers. None has survived before a Christianized version in the treatise by Vegetius (C.AD 400).
signa Roman military standards (sing. signum), including the legion’s eagle (aquila) and the flag standard of a constituent unit (vexillum). The standard was carried by the signifer.
Sol Invictus The ‘Unconquered’ or ‘Unconquerable Sun’, an eastern god equated with the Roman god Apollo.
SPQR Senatus Populusque Romanus, ‘the senate and people of Rome’. summus deus Literally the ‘highest god’ or ‘greatest god’, the ultimate guarantor of victory.
Tetrarchy The rule of four emperors, two senior Augusti and two junior Caesars, as distinct from Dyarchy, the rule of two, and Pentarchy, the rule of five.
traditores Literally ‘handers-over’, referring to those Christians who during the Great Persecution surrendered holy vessels and scripture to the authorities. From this term we derive ‘traitor’.
triumphus The triumphal entry into and procession through a city by a victorious emperor, and various associated rituals. In Greek this is the thriambos.
tropaeum The ‘trophy’, a cruciform Roman symbol of victory, later used as a battle standard. A precursor of the labarum.
vexillation A unit of the army constructed by drawing smaller groups (usually cohorts) from several regiments, initially for expeditionary undertakings or specific campaigns; in later years the groupings took on a greater permanence.
virtus A quality or group of qualities that earns an individual divine favour, the root of the English word ‘virtue’ but rather broader than that. As understood within the imperial theology of victory, it can be translated as ‘manly aggressiveness’ or ‘valour’, the reward for which is felicitas.
vota Public prayers offered for the emperor, notably at his anniversary celebrations.