The empire was overstretched at this time, basically the Bishoprics were ruled by comte (counts) who raised private armies that was made up of their vassals and local aristocracy. This meant that many regions needed to defend themselves, plus send men to areas where the field army was active along the borders. When the Viking or Saxon raids occurred it was dealt with locally, rather than as a whole.
With the death of Carloman II in 884 and Charles the fat ruling from a distance, and the death in 885 of Ragenold comte de Maine margrave of Neustria in the North fighting Vikings. This would leave a single count Odo Capet Comte de Anjou, Orleans and Tours to defend the North, South and the Paris area. Plus much of the cavalry were on service on the Breton marchers against the Vikings and Bretons who had joined forces again pushing the border back to present Mayenne/Maine river and taken Angers.
In the northern Neustria protecting the river routes from Viking raids also that occurred regularly including the previous year, with carolginian nobles employing Vikings to raid each other, plus rebellion in Burgundy, border problems in the south with the Muslims was not helping .
A shortage of cavalry was even in areas that were well known for horses such as Perche region around Le Mans, Maine who could only muster 40 mounted men to take on a raid south from Normandy and west from Bretagne where several monasteries were destroyed and Rouen sieged in the previous year.
There had been 40 years of continuous border conflict with the Vikings and Bretons, plus continued raiding along the Normandy and Belgian coast so not surprising that the Neustria administration was in trouble.
After the siege of Paris 885-886 Odo Capet, Comte de Anjou, Tours and Orleans comes to power and is voted king after the payment by Charles the fat to the Vikings. This leads to the collapse of the Carolingian empire as it breaks into a number of smaller states.
In the west the cavalry made up nobles and aristocracy and they were the backbone of the army but was small. To be a cavalryman you needed to be wealthy enough to mount yourself.
Requirement at least 44 solidos income from 4 Mansi of land (480 acres or 198 hectares) to be mounted horseman (cavallarie) and this was between 1 to 3 men per one hundred people in a Parish. (Coates) (merchants paid the equivalent if they did not own land)
Requirement
Horse and equipment
Spatha (Sword two sided blade sword with point
Saexe (short single sided knife)
Armour thorakis (could be lamellar plates or maille)
Helmet
Round Shield with boss
Leg armour (no reference if leather, splinted metal or maille)
Lance / spear
Bow (more eastern empire)
Arrows.
A cow was worth at market 3 solidos, a slave 1 to 5 (12 Pennie’s to a solidos) a good sword 8 sol, a horse 15-30 sol, horse equipment 3 sol.
1/2 penny would be a good meal and beer in a tavern, 4 penny for a barrel of wine.
Those Freemen with less income and land were foot, and needed to supply a spear and shield as minimum. Some smaller allotments could combine income to supply the parish quota for troops.
Church land also needed to provide money or men for service, this helped to create a professional foot army.
Service was required for freemen for three months. It is thought 1 in 4 qualifying men were expected to serve in some capacity over the year on the Neustria Breton marchers. 1 in 2 in upper Saxony, 1 in 6 in Lombardy, 1 in 3 on the Spanish border.
Cheers
Matt