A recurring constant in the intellectual biography of Petrarch was his massive interest in history. It is no coincidence that already in the 1320s he had copied the entire Livy obtainable at the time. Furthermore, Petrarch himself had been an active historiographer since the 1330s, when he started writing De viris illustribus.
However, Petrarch’s relevance for historiography was not founded on unveiling some detail about one or the other odd battle, consul, or emperor. It lay in his radical reappraisal and reorganization of history as such.
Since his youth, Petrarch had felt a thorough disliking of his own era (''ista aetas”) (Posteritati, 262). This is why he soon bore down on reading historians, trying to gain knowledge of another era, that of antiquity (‘‘vetustas’’) (Posteritati, 262). Thus, Petrarch constituted no less than two fundamentally divergent epochs of history, his own, and antiquity. The difference between them evidently was one of quality - antiquity, which to Petrarch primarily meant the long period of Roman dominance, was an era of peace, justice, and virtue (Alpopolo romano, 182), and, as signified by De ignorantia, the age of intellectual greats spanning from Cicero via Seneca through to St Ambrose and St Augustine. In other words, antiquity was presented as the ‘‘good’’ old days. In contrast, his own era, which had already lasted for several centuries and which Petrarch at one point referred to as the middle, “medium” age (Ad Franciscum priorem Sanctorum Apostolorum de Florentia, 322), was an era of extensive “darkness” (“tenebrae”) (Ad Agapitum de Columna, 29). In order to overcome this darkness, both morally and intellectually, Petrarch drafted the new direction with his De ignorantia. If this new path was adhered to, there was hope of the dawning of a third, more felicitous age (“felicius aevum’’) (Ad Franciscum priorem, 322).
Petrarch, thus, was the first to ever formulate a clear apprehension of the existence of epochs - both in intellectual and in real history. These eras extended over an exceedingly long time period, encompassing several centuries, and were constituted by a coherent set of specific characteristics that influenced every sphere of life. As to quantity, Petrarch defined three different eras - antiquity, the ongoing ‘‘middle’’age, and an era that he hoped would dawn in the near future. Basically, Petrarch thus anticipated the chronological classification of epochs into Antiquity, Middle Ages, and Modern Age that is still applied today. As to quality, Petrarch introduced a definite hierarchy - there was the highlight in the form of exemplary, luminous antiquity, then the low point of his own, the ‘‘middle’’ age, characterized by obstructive gloom, and then the hope of a third era in the future, when, by consequently orienting oneself on Roman models, one might be released from contemporary darkness and at least return to a relatively high level. In other words, for history in total Petrarch neither envisioned a permanent degeneration nor a continuing progress, but rather an up and down caused by mankind itself.
Both Petrarch’s high esteem of antiquity and his qualitative depreciation of the ‘‘Middle Ages’’ as a substantially ‘‘dark’’ era turned out to be exceedingly influential during the following centuries.