Humanist Latin was founded on the model of Classical Latin. We can consider Francesco Petrarch (1304-1374) as its creator, who imposed a resolutely different style than the one typical of the late medieval ars dictaminis. The authors that were deemed worthy of imitation were initially all of the ancients, however beginning notably with the late fifteenth century, the Ciceronian model was increasingly favoured to the exclusion of others. A few important exceptions should be noted, such as Angelo Poliziano (1454-1494), who in opposition to Paolo Cortesi (1465-1510) felt that the vitality of writing could not be limited by norms that were too rigid in imitation. At a time when vernacular languages acquired full dignity, Latin became the distinctive language of a restricted social and intellectual group, which through its mastery of Latin lay claim to an administrative and political role. Similarly, apparently erudite discussions on the origin of Latin–which for some such as Leonardo Bruni (1370-1444) was used only by an upper class, even in ancient Rome–helped create an image of an elitist and exclusive language.
Source : Latin in Humanist Europe