Hundreds have existed from at least the 10th century and included enough land to support one hundred families. Originally, the term referred to a group of 100 hides (units of land required to support one peasant family), whose size was related to soil conditions and terrain. According to the Oxford Companion to Local and Family History, a hide averaged about 120 acres so a hundred would cover 12,000 acres of land. In the four northern counties of England and some of southern Scotland, the equivalent division was a ward, and in the counties ruled by the Danes from the 9th through the 11th centuries, they were called wapentakes.Until the Local Government Act of 1894, hundreds were the intermediate jurisdictions between parishes and the county. The names of hundreds were taken from the original meeting places, which were away from settlements near geographic sites such as river crossings or forks in rivers.
In the south of England and the Domesday Book, the hide was used in tax assessment, and centuries of tax records are organized by hundreds. The hundred was used in other administrative, judicial and military ways. Eighteenth and early nineteenth century militia records and hearth tax returns were kept by hundreds, according to the Oxford Companion cited above. Perhaps most important were the ‘hundreds’ courts which met twelve times per year in the thirteenth century. Later the intervals varied from two to three weeks. They ended when county courts were established in 1867.
As an off-topic aside, l will mention that the term came across the Atlantic with the colonists. At one time the counties of New Jersey, Pennsylvania and Delaware were divided into hundreds. The term shows up in old land records in Virginia and Maryland as well.Susan Lewis Well, 2012