This volume showcases for the first time in the Clarendon Ancient History Series one of the best-known prose authors of classical Athens: Xenophon. Poroi (or, Revenue-Sources) was the final work of his large and varied output, written in the mid-350s BCE at a time when Athens had failed to prevent the collapse of her second Aegean 'empire', and was impoverished and demoralized in consequence. Back in Athens after a lifetime abroad, the elderly Xenophon took an optimistic view of the plight of his fellow-citizens: though their days as a free-spending imperial power may have been over, they could fall back on the city's own, unique assets - both human (the large community of resident and visiting foreigners) and material (the natural resources of Attica itself, notably the silver-mines) - strategically exploiting them in order to set the city on the road to peace and prosperity. Xenophon fleshed out this general position with many specific proposals, in doing so situating Poroi not only in a tradition of early economic thought, but also in the realm of practical politics. Framed by a General Introduction and the first-ever full Commentary on the work in English, this new and unprecedentedly accurate translation offers an authoritative yet accessible overview of the text, its context, and its historical, socio-political, and economic implications that will be invaluable to both students new to the work and to more experienced scholars. Challenging the view that there is a significant overlap between Xenophon's ideas and the policies associated (in the 350s and 340s) with Euboulos, it argues, rather, that Poroi was ahead of its time and in fact anticipated the programme of Athens' leading statesman of the 330s and 320s: Lykourgos.