Sharply marked social differentiation is a salient characteristic of Mediterranean societies. In the anthropology of the Mediterranean, inequality of social status has been analyzed so far only within the paradigmatic town/village relationship (Bell 1979; Davis 1977; Silverman 1966). None of the Mediterraneanist anthropologists, however, has studied in a systematic fashion the relationship between trade networks, as the most prominent aspect of Mediterranean communication, and the process of social stratification.
On the island of Hvar, off the Croatian coast in the Adriatic Sea, distinct social hierarchies emerged and surpassed in its elaboration the majority of other ports in the province of Dalmatia. Moreover, this social differentiation on the island is not limited to the town of Hvar, but appears clearly in the rural areas as well, a variation recorded only rarely in the Mediterranean anthropology literature (O'Neill 1987). Neither history nor ecology alone can account for the exceptional and early development of a complex class structure as it is found on Hvar, and I see its locational advantage in the eastern Adriatic communication network as the decisive factor.
The ecology of the Dalmatian archipelago allows for little differentiation in terms of natural resources. Combined with locational advantage, however, these minimal differences are utilized to the greatest benefit of some communities in the network. To demonstrate Hvar's locational advantage, I use the graph-theoretic models of betweenness centrality and neighborhood, based on the assumption that communities that are able to attract the,largest number of ships will profit from trade and fees and develop an early and complex system of social stratification. Among all eastern Adriatic ports Hvar played an exceptional role as one of the most frequented places. Mediterranean voyaging was, and still is, for the most part restricted to the conservative technique of port hopping. In the past the need for frequent stops to renew supplies of food and water, as well as for refuge from bad weather and pirates, dictated most often sailing in the daytime and staying in a protected harbor at night. The Venetian Republic built its commercial dominance on her possessions in the Adriatic. As Braudel (1972:149) wrote, " these islands, running along the axis of her power, were Venice's stationary fleet." The ability to control the sea routes through the possession of islands was the key to both its military and commercial power in the Mediterranean.
Through an application of graph-theoretic models, I will demonstrate here that the combination of locational advantage and an excellent harbor enabled Hvar to maintain the most important position in the Dalmatian archipelago during the entire period of Venetian reign. Under these conditions internal social stratification, both urban and rural, developed and was sustained through the transfer of wealth and through marriage alliances. In addition to an elaborate social stratification in towns concentrated around harbors, the rural areas on the island of Hvar also developed three main social strata differentiated by land ownership (Milicic 1992). With its relative lack of natural resources the island's production was primarily aimed for trade. Thus, for example, the rural community of Brusje, with its production first of wine and later of lavender, was directly dependent on the island's position in the trade network. In the case of Hvar the external trade network set up the conditions for internal stratification based on the differentiafion in the degree of access to exchange and, consequently, wealth.
Centrality is a concept of graph theory that can be empirically interpreted in several ways (Freeman 1979). In the case of the Adriatic trade network the concept of betweenness centrality is interpreted as the measure of the frequency of stopovers of ships sailing between Dalmatian ports. The wealth acquired from fees and taxes depends on the flow of traffic through individual ports. …