Almost all of the counties of England were organised in a similar manner in the C10th, although some variation is evident between the measurements and names in the Danelaw and those in the rest of the country.

At the heart of the government system is the hide - a unit variously used to calculate military and civil service, taxation levels, and land values. The hide is something of an oddity, varying in physical size from 20 to 120 acres depending on the area of the country and the type of land being measured. In many ways, this makes perfect sense, as 120 acres of mainly scrub and moorland in one area of the country may support the same number of people, and generate the same wealth, as 20 acres of prime land in another.

The hide has been described as the minimum area of land necessary to support a single family, but as always it is never as clear cut as this - a hide can certainly support more than a few people, and indeed in the C10th a "family" as such should be thought of more as an extended farmstead, with perhaps three generations of a family living there, plus various workers and dependents, with potentially up to 50 people living from the output of the hide.

Above the hide is the hundred - literally one hundred hides. In addition to being an area defined for ease of tax collection and management, the hundred also provided the lowest level of legal framework for the county, with a hundred court where men could be tried before their peers. This court met each month, and took a proportion of all fines levied.

In Cambridgeshire, there were seventeen hundreds at the time of Domesday, with the town of Cambridge being assessed as a hundred on its own, and the Isle of Ely assessed as a double hundred.

In social terms, the lowest levels of society were the villani or villeins, who held no land on their own account, cottars (literally cottagers, i.e. someone with a house), and bordars (small holders, who worked their own land but were also required to do work for their lord on set days, perhaps up to two days per week). The exact definition of these terms varies across time and across the country, but as a sweeping generalisation this is probably not too far from the facts.

Above these was the Thegn, originally a man of considerable power and wealth, but by the time of Domesday the system of inheritance had resulted in a breakup of many estates, and a corresponding dilution in the status of many Thegns. In theory, a Thegn possessed a church and a kitchen, a bell-tower, a fortified dwelling place, and an estate of at least five hides. In some cases, Thegns owned large tracts of land in several counties, while in many cases the holding had fallen below five hides by the time of Domesday. The worth of a Thegn was reflected in his weregild, or death compensation, of 1200 shillings, compared to perhaps up to 200 shillings for a lesser man, dependent on his status.

The Shire Reeve (later Sheriff) was the ultimate authority for the county, acting as the administrative co-ordinator in all matters, and hearing legal cases which were outside of the remit of the hundred courts. The Reeve would be expected to arrange the military levy, and would normally lead it in person.  

Working across counties, or at the head of the larger counties was the Ealdorman (such as Byrthnoth, Earldorman of Essex who fell at the Battle of Maldon in 991) who by the early C11th possibly under Danish influence had become Earls (from the Norse Jarl), who effectively took on the roles which had earlier fallen to the kings of the separate kingdoms within England. The most prominent Earls, of Mercia, Northumbria, East Anglia and Wessex, were the backbone of the royal system, and were major regional forces in their own right.  

In levying taxes and in raising military forces, the five hide unit has been proposed by some academics as a common measure. Many examples exist where taxes were imposed in values which are easily divisible by 5, 20 or 100, suggesting that the amount to be collected was allocated to each hide individually, and that each Thegn was required to collect the correct amount from among his holdings. Typically, Danegeld collection was levied at 2 shillings per hide. Similarly, the requirement for military service was that one man should be provided from each five hides, i.e. that every Thegn should provide a warrior for the levy, or fyrd. Given the neat match between the size required to attained Thegn rank, and the requirement to provide a warrior, it is a simple step to assume that the Thegn performed the military service himself under normal circumstances as a consequence of his holding, although this is not necessarily always the case. The Church was a major landowner, and so delegation of the military duty was common in some areas.

Taking the five hide unit, each hundred would be required to provide 20 warriors. The level of equipment of these warriors is laid down in several texts, with some variation between 850 and 1050, but in general the warrior was required to present himself with a horse, spear, shield, helmet, and enough food and fodder for 30 days service. To enable him to do so, the five hide unit was required to find 20 shillings to support him while he was away, which was paid to him on departure. Later, this was changed to 10 shillings on departure, and a further ten on his return.

Scaling these figures to Cambridgeshire, we can see that the full call-out of the Shire would be expected to produce 340 fully-equipped men, capable of sustaining themselves for the required 60 day period, and with transport to allow them to travel quickly over distances of perhaps up to 150 miles when required. For Huntingdonshire, with four hundreds plus Huntingdon itself answering for half a hundred, 90 men would be expected. Norfolk, Suffolk and Essex would produce 680, 480, and 480 respectively. In total, East Anglia would produce 1980 men for service.

References:

1. Frank Stenton, Anglo-Saxon England, Oxford 1943 - revised 1947, 1971 - this is still very much the core text book for the period, and although new research has challenged some parts of his work, Stenton remains the key authority for England in the Anglo-Saxon period.

2. C Warren Hollister, Anglo-Saxon Military Institutions on the Eve of the Conquest, Oxford 1962 - this provides a very good summary of the organisation of the Fyrd, and despite its age, has not been challenged to any great extent.

3. Cyril Hart, The Danelaw, Hambledon 1992 - a very detailed work with numerous maps and tables, this goes into too much depth for the casual enquirer, but provides a wealth of local information and a detailed description of the management of lanholding and taxes.