De viris illustribus
Petrarch went from these Lives of "Illustrious Men" into his work on the "Africa" using the research of "De viris illustribus" as the bases. Petrarch was preoccupied with this idea of a series of biographies of Lives of ancient heroes of generals and statesmen for almost forty years. There were several plans of "De viris illustribus". In 1348-49 Petrarch made a larger version of Lives. Petrarch writes a letter to Luca Cristiani in 1349 concerning these Lives for "De viris illustribus" that he was doing in the valley at Vaucluse in France;