I have admitted into my narrative as strictly authentic all the statements relating to Alexander and Philip which Ptolemy, son of Lagus,11 and Aristobulus, son of Aristobulus,12 agree in making; and from those statements which differ I have selected that which appears to me the7 more credible and at the same time the more deserving of record. Different authors have given different accounts of Alexander’s life; and there is no one about whom more have written, or more at variance with each other. But in my opinion the narratives of Ptolemy and Aristobulus are more worthy of credit than the rest; Aristobulus, because he served under king Alexander in his expedition, and Ptolemy, not only because he accompanied Alexander in his expedition, but also because he was himself a king afterwards, and falsification of facts would have been more disgraceful to him than to any other man. Moreover, they are both more worthy of credit, because they compiled their histories after Alexander’s death, when neither compulsion was used nor reward offered them to write anything different from what really occurred. Some statements made by other writers I have incorporated in my narrative, because they seemed to me worthy of mention and not altogether improbable; but I have given them merely as reports of Alexander’s proceedings. And if any man wonders why, after so many other men have written of Alexander, the compilation of this history came into my mind, after perusing13 the narratives of all the rest, let him read this of mine, and then wonder (if he can).