A hundred was the division of a shire for administrative, military and judicial purposes under the common law. Originally, when introduced by the Saxons between 613 and 1017, a hundred had enough land to sustain approximately one hundred households headed by a hundred-man or hundred eolder. He was responsible for administration, justice, and supplying military troops, as well as leading its forces. The office was not hereditary, but by the 10th century the office was selected from among a few outstanding families. Within each hundred there was a meeting place where the men of the hundred discussed local issues, and judicial trials were enacted. The role of the hundred court was described in the Dooms (laws) of King Edgar. The name of the hundred was normally that of its meeting-place. In England, specifically, it has been suggested that 'hundred' referred to the amount of land sufficient to sustain one hundred families, defined as the land covered by one hundred "hides".
Hundreds were further divided. Larger or more populous hundreds were split into divisions (or in Sussex, half hundreds). All hundreds were divided into tithings, which contained ten households. Below that, the basic unit of land was called the hide, which was enough land to support one family and varied in size from 60 to 120 old acres, or 15 to 30 modern acres (6 to 12 ha) depending on the quality and fertility of the land. Compare with township.
Above the hundred was the shire under the control of a shire-reeve (or sheriff). Hundred boundaries were independent of both parish and county boundaries, although often aligned, meaning that a hundred could be split between counties (usually only a fraction), or a parish could be split between hundreds. The system of hundreds was not as stable as the system of counties being established at the time, and lists frequently differ on how many hundreds a county has. The Domesday Book contained a radically different set of hundreds than that which would later become established, in many parts of the country. The number of hundreds in each county varied wildly. Leicestershire had six (up from four at Domesday), whereas Devon, nearly three times larger, had thirty-two.