The Roman Army, 31 BC–AD 337: A Sourcebook

Introduction 3
imperial speeches to the troops, since emperors sought to conceal
their political dependence on the military. Coins bearing the legend
‘concord of the armies’ provide double-edged evidence, perhaps
declaring the reality of political loyalty among the soldiers, or hoping
to instill it. Some issues, like those of Hadrian celebrating the army
stationed in its provincial billets, or of Septimius Severus in honour
of the legions that supported his bid for power in AD 193, give a
tantalizing glimpse of the importance attached by emperors to
influencing the army by pictures and slogans. The evaluation of this
kind of evidence is notoriously difficult not least because so little is
known of the process from initial decision to the end product of a
coin. How far did coin types and legends take into account the views
and prejudices of soldiers, who probably received in pay and donatives
a substantial proportion of coins issued? In what ways were emperors
personally involved in deciding how to influence public opinion
through coin types? How successful were they? How was the
presentation of ideas afffected by the degree of artistic licence to be
expected in ceremonial or memorial art?
Students of the Roman army face two main problems. First, although
there is a large amount of evidence, it forms a mosaic made from pieces
covering a span of more than three centuries. It is therefore difficult to
trace developments in the army of the imperial period, and we may indeed
underestimate the degree of change precisely because of the uneven nature
of the sources and the lack of a firm chronological context. Second, we
remain strikingly ill-informed in certain key areas, for example, the size
of a legion and its detailed organization, promotion procedures for
centurions and junior officers, the appointment of senior commanders,
strategy and battle tactics. We would like to know how often legions
and other units were up to full strength and had the approved number of
artillery pieces, and to what extent Trajan’s column, which shows the
army at its very best like a recruiting poster of a modern army, differs
from reality. In fact the wealth of evidence available is often not of the
right kind to answer some of the most important questions. We need the
reminiscences of a centurion, the personal diaries of a commander, and
memoranda of meetings between an emperor and his advisers discussing
a military crisis and planning the logistics of a campaign.
The Army of the Republic
According to tradition, king Servius Tullius (c. 580–30 BC) divided the
citizen body into classes on the basis of wealth, an action which had