Reeve (England)
Originally in Anglo-Saxon England the reeve was a senior official with local responsibilities under the Crown e.g. as the chief magistrate of a town or district. Subsequently, after the Norman conquest, it was an office held by a man of lower rank, appointed as manager of a manor and overseer of the peasants. In this later role, historian H. R. Loyn observes, "he is the earliest English specialist in estate management."
Anglo-Saxon England
Before the Conquest, a reeve (Old English ġerēfa; similar the titles greve/gräfe in Low Saxon languages of Northern Germany) was an administrative officer who generally ranked lower than the ealdorman or earl. The Old English word ġerēfa was originally a general term, but soon acquired a more technical meaning.
Land was divided into a large number of hides - an area containing enough farmable land to support one household. Ten hides constituted a tithings, and the families living upon it (in theory, 10 families) were obliged to undertake an early form of neighbourhood watch, by a collective responsibility system called frankpledge.