The middle decades of the fifteenth century, leading to the signoria of Giovanni II Bentivoglio, were a period of great political complexity in the history of Bologna. External powers – the duke of Milan and the papacy – contended for control of the city, and factions within it splintered and regrouped as events unfolded. Until 1450, the main thread in that history was the rivalry between the Bentivoglio and the Canetoli, and their factions and friends; after 1450 there evolved first a Bentivoglio-led oligarchy, then a more consolidated Bentivoglio primacy within the city. It was not until the pope decided in the 1460s to endorse the Bentivoglio that the city achieved a point of political stability. These frequent changes of regime and the progress of oligarchy, together with the abundant documentation, make Bologna in this period an interesting contrast both to other republics, such as Florence, and to more fully formed signorie such as Milan, Mantua or Ferrara.

For much of this period, the structure of government, despite frequent modification, remained largely unaltered in its broad outlines. Power was shared between the communal government and the papal legate, as laid down in successive treaties (capitoli) between the city and the popes (1429, 1431, 1447, 1466). The papal claim to appoint the governor, podestà and other officials was usually tempered in various ways (through indirect election, appointment from a prepared short-list, etc.).