determine what they should be. In the days of the great Peloponnesian war we do not hear of the Amphiktyons at all. Then and later, Athens, Sparta, Thebes, could trifle at pleasure with the rights of a weaker city, subject only to the chance that some other among the stronger cities might find it suit its interests to assert the rights of the weaker. Every Greek city had in theory an equal right to independence; but Messênê, Skiônê, and Plataia felt how hard it sometimes was to assert that right. A treaty graven on a stone went for little, an Amphiktyonic decree went for less, when a powerful and ambitious city had other purposes to carry out. Such a treaty, such a decree, went for about as much as the agreement of a modern European congress when it binds itself to secure the freedom of Epeiros and the good government of Armenia. The voice of some one overbearing city, say Sparta backed by the will of the Great King, counted for far more. The rise of the Macedonian power under two renowned princes gave the Greek world for a short space a centre and a head. International law or its substitutes went for little when Alexander, flushed with Asiatic conquest, wrote to all the cities of Greece to restore their exiles. But when the Macedonian kingdom again became only one power among many, the old state of things came back again with the needful changes. The world of Greece was no longer a world of cities only; it was a world in which cities, kingdoms, and confederations all played their part, a world in which diplomacy had its full run, in which the eastern seas of Europe were ever covered by embassies crossing one another in their endless voyages to the court of this or that prince, to the assembly of this or that confederation. It was into this busy world of complicated International dealings that the power of Rome burst like a thunderbolt. All was at once changed. Under the Roman Peace, indeed in days long before the Roman Peace was formally established, as soon as Rome became by common consent the arbiter of the Mediterranean world, International Law had small opportunities left of showing its strength or its weakness. For a while the independent powers of the civilized world received as law whatever decrees the mightiest among them, the Roman Senate, thought good to put forth in each particular case. As kingdoms sank into provinces, as independent cities sank into municipalities, the law of the one commonwealth into whose substance they were in a manner merged became the immediate law of the whole civilized world, with the might of Cæsar Augustus as its sanction. There might still be a _jus gentium_ between Rome and Parthia; to settle such questions as might arise at Antioch, at Gades, or at Eboracum, there was only the law of the Roman city of which all other cities had become suburbs.