The main inhibiting factor on Sicilian poetry was probably the political censorship imposed by Frederick: literary debate was confined to courtly love. In this respect, the poetry of the north, though stuck to the langues d'oïl, provided fresher blood for satire. The north was fragmented into communes or little city-states which had a relatively democratic self-government, and that is precisely why the "sirventese" genre, and later, Dante's "Divina Commedia" and sonnets were so popular: they referred to real people and feelings, though often idealised like Beatrice. A sirventese is, in effect, eminently political: it usually refers to real battles and attacks real military or political enemies, the author often being the soldier or the knight involved in the strife, as in Guittone d'Arezzo's "Rotta di Montaperti" (Defeat of Montaperti), a bloody battle where Manfred of Sicily, Frederick's son, defeated the guelfs. Dante himself will commemorate the event in the Commedia many years later, where, mindful of the political strife that had him exiled, he will attack many princes and popes, such as Boniface VIII, one of his biggest personal enemies.