As for his author, I shall not be ashamed to copy from the learned Casaubon, who has translated him into Latin,[12] many things which I had not from my own small reading, and which I could not, without great difficulty, have drawn, but from his fountain; not omitting some which came casually in my way, by reading the preface of the Abbot Pichon to the Dauphin’s “Tacitus,” an admirable and most useful work; which helps I ingenuously profess to have received from them, both to clear myself from being a plagiary of their writings, and to give authority, by their names, to the weakness of my own performance. The taking of Constantinople, by Mahomet the Great, fell into the latter times of Pope Nicholas the Fifth,[13] a pope not only studious of good letters, and particularly of history, but also a great encourager of it in others. From the dreadful overthrow of that city, and final subversion of the Greek empire, many learned men escaped, and brought over with them into Italy that treasure of ancient authors,[14] which, by their unhappiness, we now possess; and, amongst the rest, some of these remaining fragments of Polybius. The body of this history, as he left it finished, was consisting of forty books, of which the eighth part[15] is only remaining to us entire. As for his negociations, when he was sent ambassador either from his own countrymen,[16] the commonwealth of the Achaians, or afterwards was employed by the Romans on their business with other nations, we are obliged to Constantine the Great for their preservation; for that emperor was so much in love with the dexterous management and wisdom of our author, that he caused them all to be faithfully transcribed, and made frequent use of them in his own dispatches and affairs with foreign princes, as his best guides in his concernments with them.