"WHEREVER Ptolemy and Aristobulus in their histories of Alexander, the son of Philip, have given the same account, I have followed it on the assumption of its accuracy; where their facts differ I have chosen what I feel to be the more probable and interesting. There are other accounts of Alexander's life - more of them, indeed, and more mutually conflicting than of any other historical character; it seems to me, however, that Ptolemy and Aristobulus are the most trustworthy writers on this subject, because the latter shared Alexander's campaigns, and the former - Ptolemy - in addition to this advantage, was himself a King, and it is more disgraceful for a King to tell lies than for anyone else. Moreover, Alexander was dead when these men wrote; so there was no sort of pressure upon either of them, and they could not profit from falsification of the facts. Certain statements by other writers upon Alexander may be taken to represent popular tradition: some of these, which are interesting in themselves and may well be true, I have included in my work.
   "If anyone should wonder why I should have wished to write this history when so many other men have done the same, I would ask him to reserve judgement until he has first read my predecessors' work and then become acquainted with my own."

Arrian: The Campaigns of Alexander