For the understanding of the period of history to which the name Indo-Greek (in perhaps more precise terminology Indo-Bactrian) is usually given, the reign of Menander has to be treated as central. For the Indo-Bactrian kingdom, this reign must have constituted the main period of stability and consolidation. Whatever we can hope to detect of Indo-Bactrian organizational structure must have assumed during those years its most coherent form. They had been preceded by several decades of expansion and improvization. The aftermath, as we shall attempt to show, was one of division, perhaps of dissension. At neither extreme could we expect a pattern of administrative continuity to stand out from so fragmentary an historical tradition. Since the evidence of texts and archaeology, despite noble efforts that have been devoted to them, is alike scanty for this episode of Macedonian government southward from the Hindu Kush to the eastern fringe of the Panjāb, it is from the copious coinage that inquiry must still be made. We may fittingly dedicate to Sir Mortimer Wheeler, excavator of Menander's capital at Chārsada, a new attempt to interpret the coinage of Menander. His own authority may be cited for the judgment that previous numismatic studies, notwithstanding great merits, have not yet revealed all that the archaeologist needs to know. In an age of technological progress, it may still be said that an excavator's finds of coins, once fully understood, could continue to provide his most accurate indication of dating. The present analysis derives from an inquiry conducted at Kabul during study leave from the School of Oriental and African Studies in the summer of 1969. The writer is indebted to H.E. Dr. Muhammad Anas, Minister of Culture and Information of the Royal Afghan Government, for permission to examine the copious material of the Mir Zakah hoard; to Dr. A. A. Motamedi, Director-General of the Kabul Museum, both for the initial invitation which made the visit possible, and for his generous allocation of the Museum's facilities while the work was in progress; and to Dr. Paul Bernard for his hospitable welcome at the Délégation Archéologique Française en Afghanistan.