While costume and the arts of life had remained uniform among the Anglo-Saxons, they had on the contrary undergone a great change on the Continent. Numerous and great political revolutions, and an extensive intercourse with the Arabs and other foreign nations, had brought many modifications even into the dress of the people, particularly of the higher classes. The Normans, when they had settled in Neustria, adopted the costume and language of the Franks.
The costume of the Anglo-Normans and Anglo-Saxons differed most widely (at the time of the Conquest) in the military dress. The Anglo-Norman soldiers were covered with the haubere or halberc, a tunic of mail, either ringed, or net-work, or quilted. This article of dress was probably borrowed from the Arabs. It appears in our plate of Spanish Warriors of the eleventh century, who (with the exception of the round shield) are dressed exactly like the Normans in the Bayeux Tapestry. To the neck of this tunic was attached a cowl, which covered the head, and over which was placed the conical helm, with the long nasal guard descending in front.
The shield of the Normans was long and kite-shaped, and often bore the figure of a dragon, lion, or some other device. The Norman lance had a flag attached to it, and was called a gonfanon. The bow and the sling were also formidable instruments in the hands of the Norman soldiers. Before the end of the eleventh century, several changes had been made in the form and construction of defensive armour, and it sustained continual alterations during the twelfth century. The cowl of mail was preserved, but the helmet underwent a series of changes; the nasal defence was thrown away at the beginning of the twelfth century, and a pointed iron cap was adopted; and towards the latter part of the same century the helmet took first the form of a high cone, which afterwards subsided into a flat-topped cap of steel, fastened under the chin with an iron hoop.
A long tunic was frequently worn under the hauberc, and the latter was partly covered with a surcoat, an article of dress supposed to have been borrowed from the Saracens during the crusades. The kite-shaped shield continued in use till after the middle of the twelfth century, after which it became shortened in form till it took nearly the form of a triangle, being semicylindrical instead of flat, as the kite-shaped shield had been. Under Richard I the shield was charged with the armorial bearings of its owner. To offensive weapons, was added, in the latter half of the twelfth century, the arbaleste or cross-bow.
Source: Dresses and Decorations of the Middle Ages, Volume 1 by Henry Shaw F.S.A. (1843)