2019, ProQuest
At the beginning of the thirteenth century the commercial commune of Pisa was one of the two most powerful maritime forces in the Mediterranean, alongside Venice and ahead of Genoa. By the end of the century, however, the city had declined to a position of solely regional political and economic importance. This dissertation delves into the reasons behind Pisa’s decline during the very period when Italy’s three most famous commercial economies of Venice, Genoa, and Florence were experiencing their greatest growth. This study primarily utilizes traditional historiographic approaches for examining Pisa during the long thirteenth century, but also incorporates the interdisciplinary use of statistical and social network analyses to uncover facets of the socio-economic landscape during the final decades of the century. The strength of the present work lies in the chronological breadth of its study, encompassing just over a century of Pisan history. Unlike previous scholarship which has focused more narrowly on a few decades, a broader period of study permits the uncovering of communal behavioral trends and patterns in decision making. The causes of thirteenth-century decline can generally be divided into four categories: imperial allegiance at all costs, ignoring structural changes in the global economy, unquenchable Sardinian aspirations, and the consequences of the traumatic naval defeat at Meloria in 1284. Since at least 1081 Pisa had traded its allegiance for imperial commercial concessions, often to the consternation of the city’s mostly papally-aligned neighbors. During the thirteenth century, as imperial power in Italy waned and factional conflict intensified, Pisa adherence to the imperial strategy repeatedly brought them into military conflict with the rest of Tuscany, ultimately isolating Pisa politically on the mainland. Pisa had built its economic-political prominence primarily through the spice trade with the East and the success of its leather industries at home. Political events and changing consumer preferences conspired to move the primary trade routes northward and westward while market demand for spices was eclipsed by demand for woolen textiles; while Pisa was slow to respond to these changes, the city’s chief competitors adapted quickly and reaped the bulk of the benefits, largely excluding Pisa from later entry. In Sardinia, what had begun as a twelfth-century argument with Genoa over episcopal supremacy evolved into a land grab by Pisa’s most powerful families. As these families wielded significant political power, their personal ambitions bent communal policies to their own interests, repeatedly bringing the commune into violent competition with Genoa. One such encounter was the Battle of Meloria in 1284 which resulted in the death or capture of over 10,000 Pisan men, possibly 25% of the city’s population. This demographic tragedy, combined with the counterproductive policies of a series of strongmen and oligarchies, sent the city spiraling into a protracted economic depression. This depression, discovered for the first time by the statistical and social network analyses of the present study, crippled the already declining economic and political importance of the city, permanently removing any hope of the municipality achieving anything beyond regional importance.
Matthew E Parker