It is hardly necessary to dwell upon Petrarch's extensive correspondence. He was the leader of the learned men of his age; and it is common knowledge that all his prominent contemporaries-whether in the political world, or in the religious world, or in the scholarly world-were numbered among his friends. Corresponding so incessantly with all men and on all topics, Petrarch's letters soon grew into an unmanageable mass. One day in 1359 (Frac., Note to Fam., XXIV, 13) Petrarch, with a sigh, consigned to the flames a thousand or more papers, consisting of short poems and of letters, merely to avoid the irksome task of sifting and of correcting them. He then noticed a few papers lying in a corner, which (after some hesitation) he spared because they had already been recopied and arranged by his secretary (Praefatio ad Socratem, I, p. 15). Petrarch divided these "few" letters into two groups, dedicating the twenty-four books of prose epistles to Socrates (Praefatio, loc. cit., and Fam., XXIV, 13), and the three books of poetic epistles to Marco Barbato (Praefatio, loc. cit., pp. 15, 16, and Fam., XXII, 3).