How could you tell apart the Roman legions

Each legion and each of its units, the cohort (a bit like a battalion) and the century (a bit like a company) had its own standards and standard-bearer. The standards made them recognisable.

The military standard (signum militaris, plural signa militaria) was tall staff with a number of phalerae (metal disks), and other decorative elements mounted on it. It was topped with a leaf-shaped spear head or a hand (manus). The signum of a century had one to six disks which probably gave the number of the century within a cohort as a cohort had six centuries. The signa with fewer disks had more of the other decorative elements to cover the length of the staff. The legions and the cohorts also had their signa. For these, there was a horizontal plate with the title (legion or cohort) and number of the unit at the top of the disks and below the spear head or the hand. Two leather strips were suspended at the two ends of the plate. There could be a wreath below spear head or encircling the hand. These might have been signs of honour or awards.

The standards, with their height were easily visible and helped the soldiers to stay with their units in a battle and the commanders to identify their positions. They also acted as signalling posts. The standard bearers and the trumpeters (cornicines) stood together in front of the units. A trumpet (cornu) blow drew attention to the standard, which visually relayed the command signals of the trumpet to the ranks. Such signals were often related to movements. Therefore the standards acted a reference points for the movements of the troops and this was reflected in some of the terminology, such as signa inferre (to advance) and ad signa convenire (to re-assemble). They were important for the co-ordination of the actions of the units and to orientate the troops within a unit.

The standards also acted as rallying points, and as symbols of the honour and esprit de corps of the units. They were also considered as the sacred emblem of the unit and played key roles at religious festivals. They were anointed with precious oils and decorated with garlands. During these ceremonies, they were so revered that it was like the troops worshipped the standards themselves.

Astrological icons such as a bull, ram, capricorn, pegasus and so on were carried on a separate pole standard or were mounted on the Signum. They generally represented the period of the Zodiac under which the unit had been formed as a ‘birth sign’. There could also be other effigies relating to the origin of the unit, its founder or a particular commander under whom a great victory had been achieved. Crescents were often mounted within the group of disks. These probably represented Mithras a divinity of a mystery religion which originated from Persia and had been adopted by the Greeks. The Mysteries of Mithras were popular among Roman soldiers. An inverted metal bowl with dangling textile fringes was placed below the other elements. Its purpose or meaning is not known.

There were also standards with banners, the the vexillum (plural vexilla) which were carried by the vexillarius. It name was a diminutive of velum (Sail) and meant little sail. It was square piece of woven fabric (textilis anguis) hung on a cross bar attached to a gilt staff. This banner displayed the unit type LEG (legion) or COH (cohort), the number of the unit (in Roman numerals) and the emblem of the unit. They were used by the vexillationes (plural vexillatio), detachments of legions formed as a temporary task force. They were assembled ad hoc to meet a crisis on Rome’s vast frontiers, or to attack enemy territory. They bore the names and numbers of the ‘mother’ legion’.

The most famous standard was the “Aquila” (Eagle), the symbol of a Legion, which was carried at the head of its formation when on the march by the “Aquilifer” and was staunchly protected on and off the field of battle. A legion which lost its Aquila was disgraced. It was a symbol of prowess, rather than an identifier of the legion.

The standard-bearers played an important role in battle and were highly regarded. They were senior soldiers, often soldiers who served beyond the normal term of service. They wore lighter armour and a smaller (round) shield than the other soldiers. They wore the heads and hides of animal on top of their armour and helmets: a bear (ursus) or wolf (lupus) pelt was frequently worn by the standard bearers of centuries and cohorts. Those who led a legion wore a lion (leo).