De viris illustribus (English: On Illustrious Men) is an unfinished collection of biographies, written in Latin, by the 14th-century Italian author Francesco Petrarca.
[5] The adjacent 1476 Table of Contents introduction is old Italian and says something to the effect: Repository of the book here present where will be shown the chapters on 36 "illustrious men" whose deeds are extensively described by the honorable poet, Sir Francesco Petrarca, and beginning as appears below.
[8] Petrarch conceived his first plan for De viris illustribus of biographies of illustrious men of Jewish, oriental, Greek and Roman famous figures in 1337-38.
[9] Petrarch's earliest reference to writing a series of biographies of Lives can be found in the third book of his work Secretum which was originally written up around 1337.
[4] St. Augustine speaks to Petrarch ...thus, putting your hand to even greater works, you have tied yourself to a book of histories from the time of king Romulus to the emperor Titus, a task of immense duration and of very great labor.
[5][10] Petrarch was preoccupied with this idea of a series of biographies of Lives of ancient heroes of generals and statesmen for almost forty years.
[5] 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; ...no place had afforded me more leisure or more exciting stimulation: that solitude has permitted me to collect in one scheme outstanding men from all lands and from all ages.
[15] In the early part of the fourteenth century in northern Italy it was fairly commonplace among historians to write a series of biographies on famous men.
[16] A friend of Petrarch's, Giovanni Colonna, authorized his version of a De viris illustribus before he left Avignon for Rome in 1338.
[19] The previous historian's works of De originibus are about the origins and definitions of geographical sites, peoples, and certain stone structures.
The second plan started in 1350 entered in Christian figures, similar in style to Jerome's De viris illustribus and his "Church Fathers."
He showed to his fourteenth century readers the lessons of common sense morality that could be learned from the ancient Roman leaders and Old Testament figures.