The pervasive source problem that makes a proper history of relations between Greeks and Persians almost impossible – the absence of any historiographical record and paucity of evidence on the Persian side – must inevitably bedevil any attempt to write the history of Alexander's conquest of Iran, where these relations culminate in temporary fusion. It is clear from earlier periods that even the best evidence on the Greek side, quite apart from its bias and its focus of interest, is factually unreliable where it can be checked. Thus Herodotus gives us a Persian satrapy list differing from the great list of Darius at Behistun, and no modern ingenuity has plausibly reconciled them; to take a small point of fact: Herodotus (III.70.3) makes Hystaspes, the father of Darius, satrap of Persis (a post that may in fact not have existed at the time) when the Persian record shows he was satrap of Parthia and Hyrcania. In the case of Alexander the situation is far more unsatisfactory. The historical record as we have it is not only a Greek record, but is so much centred in Alexander's person that even the history of Greece under his rule is difficult to disentangle, despite the existence of at least some independent primary evidence and our familiarity with the general background. In the case of Iran, evidence on the last generation of Achaemenian rule (not to mention Alexander's) is so far almost nonexistent ; the background must be largely filled in by extrapolation from an earlier age, and it is in part the Alexander sources that provide us with occasional glimpses of the later Achaemenian empire. Not only do these sources give us little that does not concern Alexander's personal actions, but they are vague about, and uninterested in, institutional and topographical details, and difficult to interpret because of multiple layers of distortion due to bias and mere romance; we should be only too grateful for a Herodotus.