Our study begins with a problem. Patronage is as difficult to define precisely as are other types of complex behavior, because it shares characteristics with other categories of relations into which it merges. The Roman use of the word patronus does not offer much help, for reasons discussed in the following chapter. Anthropologists who have studied the institution intensively in the context of the modern Mediterranean world have argued about a suitably exact definition which is not so broad as to be useless. One specialist on the subject has offered the following definition: ‘Patronage is founded on the reciprocal relations between patrons and clients. By patron I mean a person who uses his influence to assist and protect some other person, who becomes his “client”, and in return provides certain services to his patron. The relationship is asymmetrical, though the nature of the services exchanged may differ considerably.’ Three vital elements which distinguish a patronage relationship appear in this passage. First, it involves the reciprocal exchange of goods and services. Secondly, to distinguish it from a commercial transaction in the marketplace, the relationship must be a personal one of some duration. Thirdly, it must be asymmetrical, in the sense that the two parties are of unequal status and offer different kinds of goods and services in the exchange — a quality which sets patronage off from friendship between equals.

Something recognizable as patronage, thus defined, appears in histories and monographs concerning the Principate, but it has not received a systematic treatment. Nor has it received more than scattered attention in the recent social histories of the early Empire.