History of the study
The study, it seems, evolved during the Renaissance from a piece of bedroom furniture: the writing desk, escritoire, or secretary, in which a man traditionally kept his ledgers and family documents, usually under lock and key. Personal privacy as we think of it scarcely existed prior to the Renaissance, which is when the wide-open house was first subdivided into specific rooms dedicated to specific purposes; before that time, the locked writing desk was as close to a private space as the house afforded the individual. But as the cultural and political currents of the Renaissance nourished the new humanist conception of self as a distinct individual, there emerged a new desire (at least on the part of those who could afford it) for a place one might go to cultivate this self—for a room of one’s own. The man acquired his study, and the woman her boudoir.
Probably the first genuinely private space in the West, the Renaissance study was a small locked compartment that adjoined the master bedroom, a place where no other soul set foot and where the man of the house withdrew to consult his books and papers, manage the household accounts, and write in his diary.