In the thirteenth century, the governance of italian city-states became increasingly:

I think there could be a couple terms you could use to answer that question.  One might be fractious -- lots of friction and competition for power.  As a result, certain nobles would position themselves to become "Signori" or lords of the cities.  As individual noble families took on a larger role of power that way, the Italian city-states also thus became more oligarchic.  Oligarchy is a word that comes from ancient Greek, meaning "rule by a few."