The scara of Charlemagne were quartered near the king’s palace; and later in garrisons in key fortresses. The term scara is an imperfectly understood term; but seems to refer both to the elite mounted warriors (caballarii) who were the core of the Frankish army as a whole, and to the formations or regiments of this group. Further, the scara of Charlemagne seem to have been divided into three bodies (or ranks of senority?): the scholares, the scola, and the milites aulae regiae. A tentative explanation is that the scholares were an inner bodyguard of the king (the term obviously derived from the elite guards units of the late Roman Empire, and contemporarily an Imperial Guard regiment of the Byzantine Empire); the scola the guards regiment as a whole; and the last seeming to translate as the “Soldiers of the Royal Court”. In the following century, the term milites came to mean an armored professional mounted warrior; the progenitor of the Medieval knight. So perhaps the milites aulae regiae were all those members of the scara not designated as “Royal Guards”, but quartered in proximity to the palace.
Contemporary representations of Carolingian foot may be dismounted caballarii of the Scara
Another term sometimes used is “palatina“. This is another late Roman military term, used to designate elite formations of the army that were quartered near the capital. It is possible that in Carolingian parlance, the term may have been used to indicate all three of these categories of scara; who were quartered near the king/emperor’s residence. It is from this term for Charlemagne’s elite palace soldiers that the word paladin derives. In the 11th century chansons (chansons de geste), these paladins were a dozen champions of the Emperor’s court. Its possible that if indeed the Scholares were the Emperor’s bodyguards, that this group numbered a dozen and was the ultimate source of the legends of the Paladins.
The caballarii in the armies of Charlemagne and his immediate successors were relatively few in number, though an exact figure cannot definitely be given. The lowest number suggested by scholars is 5,000 for the entire empire (Delbruck); and a high number of 35,000 (Werner). this latter figure seems absurdly inflated, considering the prohibitively high cost of warhorses (up to twelve times the cost of a cow), not to mention the cost of their feed and maintenance. Large warhorses, capable of carrying a minimal of 250lbs of armored man, were in short supply. However, throughout the Carolingian period the kings made every effort to increase the size of their herds. At the Battle of Montfaucon, in 888, the Franks may have had as many as 10,000 mounted men (though, again, this may be exaggeration by the sources).
Merovingian kings inherited Roman horse farms in Gaul, and these were maintained and enlarge where possible. Warhorses were large, strong animals; 15-16 hands in height and between 1,300 and 1,500 pounds. Maintenance of the royal herds was under the authority of a court official titled comes stabuli (“Count of the Stables”, or Constable). By the Middle Ages, this officer would become the senior military leader in the realm.
Those caballarii in attendance upon Charlemagne and quartered about his palace were likely less than 1,000 in number. There is speculation that all scara units were organized into regiments of 300 caballarii, and further divided into 50-men sub-units called cunei (derived from the Latin cuneus, or “wedge”, in the late Roman army a cavalry detachment).
A fully armed caballarius was expected to have a helmet, body armor (called brunia, similar to the Scandinavian term for a mail shirt, byrnie), spatha (sword), and lancea (spear). The latter was 8-10 feet in length, with an extended and sharpened iron head. The caballarius of Charlemagne used the spear overhanded or underhanded, as a thrusting weapon; or threw the spear at close quarters. The technique of couching the lance tightly in the rider’s armpit, the most popular technique for knights throughout the Middle Ages, did not come into use until the late 11th and or early 12th century. Horsemen from the Spanish or Breton Marches were often lighter, and used javelins from horseback in the Roman manner.
In battle the caballarii fought in tightly-packed units, each 50 man cunei operating under its own banner. (This is the origin of the later Medieval conroi.) Against lighter cavalry, such as the Magyars, the Franks would use their lighter cavalry to feign flight, drawing the Magyar horsemen into a pursuit to where they could be ambushed by the heavier caballarii waiting in a concealed place. The armored caballarius were encouraged to charge in tight formation, defending against the Magyar’s arrows with their shields and coming to close-quarters as rapidly as possible.