The economic and political development of the Greek states from the eighth century onwards left few, if any, of their tribal organizations unaffected; as these became unworkable or unpopular, the traditional divisions into tribes, phratries, and gene, based in practice, if not in origin, on kinship, were sooner or later replaced or modified. But the factors which led to reform were many; it might be the problem of a subject population, a mixed population, a shifting population, or of synoecism; it might be the need for military reform; or simply a question of political feeling, an attempt to satisfy anti-aristocratic prejudice by destroying the essentially aristocratic kinship system. More than one factor could be involved in any change; each might have a different effect on the result. Consequently the process was not simple or uniform; the new order might be wholly artificial or merely a modification of the old; the old might be discarded or retained alongside the new for some special purpose; old names, proper or generic, might still be used in the new system at the same or even at a different level. In such confusion it is essential to analyse in detail the evidence for each organization on its own before looking for any general pattern or arguing by analogy from one state's system to another.
In the case of Chios the relevant documents have often been interpreted in the light of what was known of the gentilicial system of Attica. Tribes, of number unknown, were thought to have been divided into phratries, each composed of several smaller units of two kinds, gene and thiasoi. The comparison is misleading. The constitution of the Attic phratries is far from clear, but, whatever it may have been, these documents from Chios, of which the text is given below, must belong to a very different order.