In the Introduction and first two chapters of this book it was recognised that the migration of foreign merchant families to London and provincial centres was a salient feature of British mercantile development in the eighteenth and nineteenth centuries. The policies, development and contribution of these families must now be given closer attention. They had a distinct character for which ‘international houses’ seems the best epithet. Their characteristic form can be traced back to the Florentine banks of the middle ages, which consisted of a parent partnership, characteristically located in Florence, with a controlling interest in several subsidiary partnerships, one for each branch abroad. For later centuries an international house may be defined more generally as a merchant enterprise simultaneously functioning in two or more countries. The organisation persisted from the middle ages, but did not receive a major fillip until economic expansion coincided with persecution and dispersion of religious minorities in the late seventeenth and eighteenth centuries.

The outlook and practice of the international houses is best identified in relation to more familiar European and American mercantile habits and conventions. Postlethwayt explained in 1774 that ‘The most capital houses of mercantile trade throughout Europe being generally composed of several partners, it is customary for one or the other to travel into foreign countries to make better judgement of the credit and fortune of their correspondents, cement ties of commercial friendship, and extend their traffic in general.