Saracen Slain by a Christian Knight,
west lintel frieze, c.1123AD, Angoulême Cathedral, France.
Although rarely mentioned, the Phrygian-shaped helmet of the Saxons constantly appears in manuscripts of the 10th and 12th centuries.
In this example, from Angoulême Cathedral and dated c. 1123, the bottom edge at the rear is extended to protect the neck.
Such helmets appear in illuminated manuscripts and sculptures as late as c. 1218.
Source: p.8, Armies of the Crusades (Men at Arms Series, 75) by Terence Wise
The right-hand figure is referenced as figure 294 in Arms and Armour of the Crusading Era, 1050-1350, Western Europe and the Crusader States by David Nicolle
294 ‘Moor Slain by a Christian Knight’, carved frieze, County of Angoulême, c.1125
(in situ west door of Cathedral, Angoulême, France)
Both Christian victor and defeated ‘Moor’ wear the same kind of armour on this relief.
It is almost certainly not intended to show scales but is one of many current conventional ways of indicating mail.
A scale hauberk would be most unlikely to include a coif and could not have had scales beneath the armpits.
In fact almost all known scale armours have flap-like sleeves in which the scales only protect the outer part of the limb.
As such they are closer in form to lamellar armours than to mail.
This man's hauberk has a slit at the side through which the hilt of his sword protrudes, the weapon being supported beneath the hauberk.
As a ‘Moor’ or ‘Saracen’, the warrior also carries a conventional round shield, but his helmet is of a very interesting form.
It has a slightly forward-angled crown, an apparently fluted surface, and may also be extended at the back to protect the neck.
See also a series of 10 painted windows, depicting the Crusade, in the monastery church of St Denis in Paris, France.
Other 12th Century Illustrations of Costume and Soldiers