Evidently, study of local social units and structures is really study of that layer of societal detail upward from that of overall population. It is the level of names and locations at which much written local history is directed, a body of inquiry of significance and subtle variety. The attributes of local associations mean that they lend themselves especially well both to research and to history writing. It is thus unsurprising that so many small histories are devoted to institutional topics. Local population change and growth are closely associated with urbanisation and industrial development of the place, and of its region. But such growth and change is not merely a matter of human numbers or of area of occupied land. As towns grow in size and population, they also grow in social complexity. Growing towns develop the social structures and institutions required for social administration.