The transformation of the government from a broadly based ruling class to a de facto hereditary oligarchy, ultimately formalized as a senatorial nobility or patriziato, took place over a period of centuries in three distinctive phases related to factional struggles and innovations in political institutions. During the first phase, between 1376-1447, a period of changing governments (the “signoria” of the guilds and popolo, the lordship of Giovanni I Bentivoglio, a return to Milanese domination) and new political institutions (the balìa of the Ten, followed by the new executive body of the Sedici riformatori), a group of “notables” emerged from among the populares who found representation in the executive body of the anziani. (In 1453 members of the guilds of the notaries, bankers, drapers, and silk entrepreneurs were ranked in sumptuary legislation in the same class as those holding titles as knights and nobles.) In the second phase, 1447-1506 (from the concordat negotiated with Pope Nicholas V to the incorporation of Bologna directly into the Papal State in 1506), the Bentivoglio faction gained dominance, a triumph recognized by the pope’s enlarging the size of the Sedici to 21 families in 1466, and the families holding that office became a life-long and self-reproducing (de facto a hereditary) body. Thus a two-tiered oligarchy emerged in this second phase: on the lower level the families admitted into the anzianate (the members of the ruling class) and on the higher level those families admitted into the Sedici (who comprised the real leaders of the commune). In the third phase, 1506-1590, beginning with the overthrow of the Bentivoglio regime and exclusion of that faction, the papacy promoted pacification between the Pepoli and Malvezzi factions and expanded the executive body (formerly the Sedici) to a Senate of Forty and then to Fifty (1590) to include those factions and other notable families from the populares. During this process admission to the anzianate was defined formally (in 1584) as concomitant with those holding full citizenship (amplissima); admission to the Senate (the “civic nobility” or patriziato), however, remained instead a matter negotiated between the papal sovereign and the oligarchy.
