Architectural historian Mark Girouard (The Victorian Country House, Sweetness and Light: The ""Queen Anne"" Movement) has opened up an absorbing and highly promising field of study by looking into the social arrangements that shaped the country house from the Middle Ages onward. As he notes in a brief but far-reaching introduction, land meant tenants (first as soldiers, then as political supporters) plus their rents, and thus represented, for many centuries, ""the only sure basis of power."" Landed estates introduced town customs and culture to the countryside until, in the 19th century, town and country parted ways: the landed gentry became the agricultural party, as opposed to the town-dwelling middle classes. At the same time, the multi-class medieval country household--eating in one great hall--split into higher and lower orders rigorously separated by a green baize door. The permutations of this change, minutely traced and sumptuously illustrated, include the tower mystique which long outlasted any need for protection; the evolution equally of libraries and galleries and sanitary facilities; the hierarchical implications of the formal house, suited to absolute monarchy, and the substitution of ""a series of communal rooms for entertaining"" with the appearance of 18th-century ""polite society."" Then, with the popularity (and profitability) of agricultural ""improvement"" and the advent of turnpikes and railroads, country squires could enjoy nature without being imprisoned by it. The house sank into the ground, opened up to the outdoors, and sprawled asymmetrically: ""to make a house lopsided became a positively meritorious gesture, an escape from artificiality."" A thoroughly intelligent and engaging book.