Hertfordshire is a historic county immediately north of London, bounded by Cambridgeshire to the north, Essex to the east, Bedfordshire and Buckinghamshire to the west, and Middlesex to the south. Eighteenth-century surveys measured it at thirty-six miles long and twenty-eight broad, some 451,000 acres divided into eight hundreds, with nineteen market towns and 120 parishes and a population of nearly 83,000. The county took its name from Hertford, the county town, and was renowned above all for the quality of its air, said to be so conducive to health that physicians routinely recommended it, and a local saying held that anyone buying a house in Hertfordshire paid two years' extra purchase price simply for the goodness of the climate.
The soil, marled in the northern parts, produced particularly good wheat, while barley and malt were also leading commodities, the county supplying much of the malt used in London's brewing trade. Watered chiefly by the rivers Lea and Colne, Hertfordshire's proximity to the capital made it, even in the eighteenth century, a favoured location for the country houses of London merchants and gentry, its gentle, well-wooded landscape offering an easy retreat within a day's journey of town.
St Albans Abbey, founded in 793 on the traditional site of Britain's first Christian martyr and raised over the Roman city of Verulamium, was easily the county's greatest antiquity, its great tower still built largely of reused Roman brick. Hatfield House, seat of the Cecil family, and Cassiobury and Gorhambury among the county's notable parks and houses, reflected Hertfordshire's long-standing role as a favoured county of the aristocracy and gentry, a character that persisted even as London's suburbs began, by the twentieth century, to encroach steadily upon its southern edge.