Taken from The Armour of Imperial Rome
by H. Russell-Robinson
(1975, Arms and Armour Press)

For the uninitiated distinguishing the Imperial Gallic C from an Imperial Italic E can be pretty daunting. Even those who have made a study of the system can keep discussing the exact differences between a Montefortino A and B.

The problem is that the artifacts the system is based on, do not come with a stamped marking saying which type they are supposed to be. So all one can do is try to determine where it fits.

Since The Armour of Imperial Rome is long out of print, it is not easy to get a hold of the exact criteria Russell-Robinson used to classify Roman helmets. That is why they are reproduced here.

For a chronological overview of the different types, as well as a concordance between the Robinson and continental system, go to the equipment section of Romancoins.info.

Montefortino 'A'

• Bronze helmet - skull worked from one piece of metal. Form tends to be bulbous and drawn up at the apex to terminate in a hemispherical knob generally decorated with a scale pattern. In some instances the knob is undecorated and inclined to be conical with a flattened top.
• The lower rim is drawn into a short, sloping neck guard at the back and the edge is 'knocked-back' and given a half-round section.
• The border is generally given a cable finish. Above it, across the brow and on the neck guard are filed horizontal lines and flutings.

Montefortino 'B'

• Similar to Type A, except that the decoration is simplified or completely omitted.
• Crest knob is generally of the plain conical type with a flat top.
• The lower rim is a simple sloping flange, which deepens towards the back to form the neck guard. One or two rivets used to secure the cheek guards.

Montefortino 'C'

• The skulls are less bulbous and have a tendency towards being conical.
• Crest knobs are small and plain, some still rounded, some conical and others conical with a flattened top. 
• The lower rim, though thickened is much reduced in size and the neck guard tends to be broader and flatter than in other types.

Montefortino 'D'

• Crest knobs are separate castings, soldered to the bowls. 
• A strong lip is worked in the lower rim and continues on the underside of the neck guard to a lesser degree.

Montefortino 'E'

• More fully developed than the Type D, having the broad flattened neck guards and reinforcing peaks of their Coolus type contemporaries.
• They retain a hollow crest knob that appears to be made in one with the bowl. The line of the neck where it rises from the centre of the crown does not always display the continuous flow of lines seen on earlier examples.

Montefortino F

• A bulbous skull with the lead-filled and pierced crest knob forged in one with the apex.
• The turned out flange at the lower edge can be traced back to Montefortino helmets of the second to first centuries BC. [This helmet was never fitted with a brow reinforcement.] 
• The cheek piece has no raised detail such as are normally found on Gallic examples, nor is there a throat flange.

COOLUS

Coolus 'A'

• Simple hemispherical bowls with a small projecting peak at the back. The lower rim at the front and sides was 'knocked back' to form a thickened lip that did not usually carry on to the edge of the neck guard.
• Some examples have simple lines of punched ornamentation and some have a roped border like the early Montefortino types, though others are plain and unadorned.
• They have a single hole or rivet at the side for attaching the chin strap or tie. Roman 'jockey-cap' helmets always have two, sometimes three, rivets to secure the cheek plates. 
• There is no form of knob or plume attachment. In most cases there is a hole in the centre of the neck guard or just above on the occipital region for a carrying ring or a third attachment point for a chin tie.

Coolus 'B'

• Bowl is rather globular with the rim flanged at the bottom and sides, running into the very small neck guard. 
• There is no provision for a reinforcing peak.

Coolus 'C'

• The skull is bulbous and low in height. 
• The neck guards are small and flat and swelling a little at each side before curling in to join the sides of the bowl.

Coolus 'D'

• Skulls are of moderate height.
• Lower rims are 'knocked back' to a rectangular section.
• Small neck guards have a thickening on the underside edge.
• Applied crest knob can be (a) small, solid conical-headed or (b) slotted to take a crest.
• Reinforcing peaks are of right-angled section. 
• [May be contemporary with Montefortino D.]

Coolus 'E'

• Bowl height varies considerably in this group.
• Reinforcing peak is a flat, curved strip of bronze, riveted at each end to the skull and tongued at the centre where it is passed through a slot in the front of the skull and is then bent over.
• Lower rim, although 'knocked back', seldom shows more than a slight projecting lip, which may continue around the upper edge of the neck guard. 
• Crest knobs are slotted from front to back.

Coolus 'F'

• Similar to the 'Coolus E', but the neck guard is made broader at the sides where it terminates with a short, angular step instead of curving in to join the lower rim.

Coolus 'G'

• Distinguished by the increased size of the neck guard - almost twice the width of previous designs.
• Reinforcing peaks are flat strips of bronze that vary in thickness.

Coolus 'H'

• The skull is a low hemispherical bowl with a broad flat neck guard the projects at right angles to the sides.
• The peak is of right-angled section and tapers in to the point of attachment at each side. 
• The lower rim across the brow is finished with a band of filed moulding (possibly inspired by the applied bronze strip on Imperial Gallic helmets).

Coolus 'I'

• Have a deeper bowl in the occipital area, with very broad neck guards. This results in a 'step-down' at the rear of the helmet.
• There may be a carrying handle on the neck guard.

AGEN-PORT

Agen-Port 'A'

• A deep, rounded bowl with vertical sides, flaring into a brim at the lower edge. • Brim is narrow at the front, widening to almost twice the breadth to form the neck protection.
• Neck guard is embossed with two shallow steps to give greater rigidity. 
• Above the brim (2-3 cm) is embossed a bold horizontal rib of triangular section, which completely encircles the bowl.

Agen-Port 'B'

• Bowl is similar to the 'A' type.
• There is no brim and only a very narrow peak at the front, formed by turning out the lower edge of the bowl.
• Embossed at the front is a pair of gently curving eyebrows of bold triangular section. 
• At the rear, the skull is extended downward to the depth of the wearer's ears and is embossed with two bold horizontal ribs, below which the edge is flanged outwards to form a neck guard. The ends of the neck guard taper into the sides.

IMPERIAL GALLIC

Imperial Gallic 'A'

• Clearly descended from the Agen-Port type. Bowl has vertical sides, flat in top and simple, but prominently embossed 'eyebrows'.
• There are two pronounced ridges in the occipital area. • The neck guard is stepped with a suspension ring riveted beneath. Its section is also like that from the Agen-Port type. 
• First helmet of this type to show a heavy reinforced peak.

Imperial Gallic 'B'

• A well-formed hemispherical bowl, prolonged at the rear of the occiput, where it is flanged outwards into a sloping neck guard of moderate proportions.
• There are cut-outs at the sides for the ears, with their edges flanged outwards.
• Brow is embossed with slender, curved 'eyebrows' or bold triangular section. 
• The occiput carries two transverse ridges and the neck guard two steps.

Imperial Gallic 'C'

• Little difference from the Type-B above. The ears have no guard. The 'eyebrows' have been given a more elaborate treatment. They are strongly curved with a deep medial step.
• There is a bronze holder for the crest box, with two slots for the two-pronged crest support. 
• The neck guard has a much broader flange with pronounced embossed steps.

Imperial Gallic 'D'

• The hemispherical skull was deep and followed the shape of the head closely.
• The 'eyebrows' were of a bold re-curved form with four equal ridges. The lower edge of the brow was decorated with an applied and embossed bronze trip. 
• There were applied ear guards of iron. The reinforcing peak had its broad outer edge inlaid with a herringbone pattern in bronze.

Imperial Gallic 'E'

• There are three steps on the occiput and two on the neck guard. The latter projects more at the sides than type D above and it has rounded, angular corners. 
• The brow band and cheek pieces are similar in pattern to those on Type-D.

Imperial Gallic 'F'

• On one sample, the brow-band is a strip of multi-reeded silver.
• The embossed steps on the occiput and neck guard are of normal pattern, though somewhat shallow.
• Where the cheek-pieces survive, they appear to be of a less elaborate form than usual, with rounded projections.

Imperial Gallic 'G'

• The skull is hemispherical with broad, leaf-like 'eyebrows' embossed at the front.
• The stepping on the neck guard and the rear of the occiput is shallow and the neck guard is almost flat and of moderate size, with rounded corners similar to the 'D' & 'F' types.
• Three decorative bronze rivets, one at the centre and one at each side of the neck, are usual, together with a pair either covering or securing the rivets, hold the cheek guard hinges in the vicinity of the temples.
• The brow reinforce is a flat sheet of iron, tongued at the centre and riveted at the extremities to the sides above the ear guards.
• Cheek pieces are fully developed with neck-flanges, bronze edge bindings and three ornamental bosses. 
• There is a bronze carrying handle attached by two split pins at the upper surface of the neck guard.

Imperial Gallic 'H'

• A variation of the Type-G. The main difference is that the angle of the neck guard is deeper, at around 50o.

Imperial Gallic 'I'

• Basically the same pattern as the Type-H, but in bronze. 
• The 'eyebrows' are of a broad leaf-like form, with a medial step above centre and a ridge at the lower border.

Imperial Gallic 'J'

• Very similar to Imperial Gallic Types G, H and I, except that the neck-guard is much larger and slopes downwards at an angle of around 45o.

IMPERIAL ITALIC

Imperial Italic 'A'

• The skulls no longer have the crest-like medial ridge.
• The deep guard for the occiput does not fit the head closely but follows almost a straight line from the back of the skull to the small right angle flange on a level with the base of the wearer's ears. 
• The brow area is embossed with a shallow inverted 'V' with scroll terminals, below which is a horizontal embossed rib that runs parallel to the straight lower brim across the brow.

Imperial Italic 'B'

• The deep iron skull is plain at the front and now lacks its reinforce.
• The ear guards are turned out flanges of the ear recesses.
• The narrow neck guard with rounded angular corners at each side has half of its width taken up by a single embossed step. This has no central recess for the suspension ring rivet. 
• Bronze edge bindings and enamelled bosses were applied to the cheek pieces and neck guard.

Imperial Italic 'C'

• Of bronze.
• The skulls were made without the embossed eyebrows of the Imperial Gallic types. There are three embossed ridges on the occiput and a single indented one on the neck guard. The latter are broad and flat, with rounded outer corners. 
• The reinforcing peaks are of right angled section instead of the heavy strip applied to the Gallic types - more similar to the Montefortino and Coolus helmets.

Imperial Italic 'D'

• An iron helmet, similar to Type-C above. The reinforcing peak is flattened and tapers to a thin forward edge. This is of bronze and shorter than normal. It is riveted in line with the cheek guards instead of over the ears.
• The helmet is embellished with a characteristic applied ornamentation of bronze sheet strips and brass eagles/temples/altars. Brass ear guards are applied and retained with three rivets apiece. 
• The neck guard has a broad edge binding and is fitted with a carrying handle.

Imperial Italic 'E'

• Like Type-D, it is of iron. It differs in that the flange of the neck guard slopes instead of being flat.

Imperial Italic 'F'

• The brow reinforce consists of a strip of iron raised into a demi-oval section and tapering towards its ends. 
• It has a shallow skull, to which a narrow iron brow band was added to give a little more depth at the front.

Imperial Italic 'G'

• Of iron, with a well-formed hemispherical bowl with recess for the ears.
• There are three transverse embossed ridges at the occiput and three semi-circular steps on the broad, slightly sloping, neck guard.
• The brow band (of bronze) is reeded and stamped with a pattern of laurel leaves and berries in pairs and this is soldered to an applied strip of iron.
• The reinforcing peak is of iron and of right angled section, with an applied bronze strip on the down turned flange. 
• The skull is crossed with two iron bars of semi-circular section.

Imperial Italic 'H'

• Made of bronze and has a well-formed hemispherical skull with bronze ornamentation soldered in place.
• There is a deep extension for the occiput and the back of the neck that terminates in a broad sloping neck guard of slightly convex section.
• At the apex of the skull is a domed button surmounting a double-stepped base from which depend four broad strips with a moulded central rib at the back, front and sides. These join the brow band, ears guards and extension for the occiput. This latter has five prominent transverse ridges instead of three.
• The peak is of a right-angled section and curved in the normal manner.
• The ear guards are of the widest possible form and rounded on the upper surface.
• The neck guard has reached its widest and largest form here and is decorated with various ornaments, e.g. a tabula ansata beneath the carrying handle.

AUXILIARY INFANTRY

Auxiliary Infantry 'A'

• Of the form of Coolus Type-I, but lacking the qualities of a legionary helmet. The bowl is straight sides with a flattish top at the centre. There is no thickened edge. 
• Where the line of the neck guard rim steps down in the region of the ears, one side is cut at an angle of 45o and the other is a right angle.

Auxiliary Infantry 'B'

• A very simple bronze skull, having straight, sloping sides with a flattened, rounded top. At the rear, the skull reaches the level of the wearer's ear lobes. 
• The reinforcing peak is placed high up and close to the extreme curve of the bowl.

Auxiliary Infantry 'C'

• Bronze. A hemispherical bowl, with a strong, upstanding cross reinforcing.
• The reinforcing peak is flat and crescentic, riveted at each side and with a central tongue passing through the helmet before being hammered over inside. 
• The back rim is slightly flanged outwards.

Auxiliary Infantry 'D'

• This type shows eastern influence. It is bronze, of globular form in the lower half, rising into a hollow conical apex surmounted by a conical button on a double-stepped base. Just behind the wearer's ears, there is a right-angled step down. To this extension, a neck guard would have been riveted (or a mail coif).

AUXILIARY CAVALRY

Auxiliary Cavalry 'A'

• The skulls are hemispherical with recesses for the ears and with deep extensions at the occiput terminating in rather small neck flanges of about the same proportion as those on cavalry sports helmets.

Auxiliary Cavalry 'B'

• Similar to the previous type, but with a more sloped and slightly broader neck guard.
• The upper part of the skull is of iron, with a bronze casing. 
• There are large bronze bosses attached to the neck guard, to the occiput area and just above the ear protectors. There is additional decoration to the casing in the form of punched raised lines.

Auxiliary Cavalry 'C'

• Made from one bronze plate.
• From the apex of the hemispherical skull, a short point of triangular outline has been raised.
• The back is deep and terminates in a small, slightly sloping, neck flange. 
• An embossed rim crosses the brow and runs into the rather shallow ear guards, made in one with the rest. Above these, and following their outline, is an embossed rib.

Auxiliary Cavalry 'D'

• Has a well formed hemispherical skull with a very deep back that brings the broad neck guard almost to the shoulders.
• There are applied bronze ear guards with broad flanges and the brow plate is brought to a central point on the lower rim.
• A low crest runs from just forward of the centre of the crown to a short distance above the neck flange where it is secured by a large cone-headed rivet at each end.
• The neck guard is bound at the edge with a bronze rim. 
• The cheek pieces were extremely large and enveloping and with very wide throat flanges.

Auxiliary Cavalry 'E'

• Very similar to the previous type, but with in addition a transverse reinforce for the skull.

Auxiliary Cavalry 'F'

• Very similar to the previous two types, but with no applied decoration.
• The ear guards and border across the brow were raised out of the skull piece.
• Ball-headed rivets were used to secure the peak and reinforces, instead of the cone-shaped ones. 
• The edges of the neck guard have been notched to retain the edge binding.

Auxiliary Cavalry 'G'

• Has a transversally ridged brow plate embossed with projecting laurel and oak leaves and also a central human bust. 
• The neck guard was quite wide, compared to the other types.

Auxiliary Cavalry 'H'

• Made of iron with applied bronze sheet decoration. This last is engraved with feather-like scaling and writhing serpents.
• In the centre of the crown is an anther - a hollow bronze knob rising from a convex square base. This represents a poppy seed case.
• The brow band has a pointed peak on the lower rim. 
• The neck guard is wide, and considerably dished (similar to the Infantry Imperial-Italic Type-H).

Auxiliary Cavalry 'I'

• A plain, deep helmet with a large neck guard of the same shape as the previous type.
• The ear pieces are very large and the rounded shallow ear guards are worked out from the edges. 
• An upturned pointed peak is attached to the rim above the brow.

CAVALRY SPORTS

Cavalry 'Sports' 'A'

• Possibly Hellenistic in origin. Has a shallow skull that reaches just below the tips of the ears at the back. 
• There are no projecting ear guards.

Cavalry 'Sports' 'B'

• Have a distinctive high projecting peak rising from the brim of the skull piece. 
• The skull pieces are made like ornamental helmets, with heavily embossed, though crude, figures.

Cavalry 'Sports' 'C'

• In the form of an idealised male youthful face, with boldly embossed wavy hair across the brow.

Cavalry 'Sports' 'D'

• Horizontally placed hinge, attaching the mask to the skull piece. 
• The skulls are made to represent elaborately decorated helmets.

Cavalry 'Sports' 'E'

• The masks represent female faces.

Cavalry 'Sports' 'F'

• These have a removable central area of the mask that covers the eyes, nose and mouth. 
• The helmet is divided into two parts on the line of the ears.

Cavalry 'Sports' 'G'

• These helmets have a high arched crest.

Cavalry 'Sports' 'H'

• The skull is of a debased 'attic' form. 
• The crest does not rise as high as the 'G' type.

Cavalry 'Sports' 'I'

• Of an 'attic' form, with an embossed brow band or forehead plate, rising along its upper edge into three rounded peaks.

Cavalry 'Sports' 'J'

• In the form of a tall, Phrygian cap with a forward curving apex in the form of an eagle's head.