It seems almost incredible that a clear-headed man should have entertained a programme of such magnitude. But we must remember that never had human beings more clearly performed the obviously miraculous. We know, on the authority of a German military expert,[19] that, had the host which followed Xerxes to Athens numbered the 5,283,220 men attributed to it by Herodotus "without taking count of women cooks, concubines, eunuchs, beasts of burden, cattle, and Indian dogs," its rear guard must have been still filing out of Sardis while its van was vainly storming Thermopylæ. But what Herodotus reports is what the Athenians believed. They had met and routed the might of all Asia. They had mastered in fair fight the conquerors of all other peoples. The world was theirs: it was merely a question of taking possession.
Themistocles had, accordingly, to reckon with a national self-confidence which knew no bounds. And this had been increased by famous victories of Cimon over the Persians, and a revolt of the Helots which disclosed the fatal weakness of Sparta, when in 461 B.C. the task of conducting the fierce current of national energy, first for fifteen years (461-446 B.C.) in a heroic, but fruitless, struggle by sea and land against the Greeks and Persians simultaneously, and then for fifteen further years (446-431 B.C.) in the prosecution of glorious works of peace, fell upon the broad shoulders of Pericles, Xanthippus's son.
It is conceded that there is no taskmaster so ruthless as one's own will. The impulse to action during this strenuous epoch came from the Athenian people itself, not from its chief statesman. That fact does not, however, diminish the credit of Pericles. The golden age of Greece is, properly speaking, a golden age of Athens, and to its birth many things contributed; but decisive among them, in addition to the intensity of national life already alluded to, was an unrivaled facility for great leaders to get into effective contact with the masses under conditions in which there was the fullest opportunity for men in general to use their natural powers to the utmost. This happy combination of creative genius and receptive multitude arose in the main from the democratic institutions of Athens; but, for the public and private wealth without which Athenian democracy proved unworkable, and for the imaginative stimulus which enterprises of great pitch and moment alone give, the possession of empire was, perhaps, essential.
In the age of Pericles, Athens was a city with a population of about 150,000. Attica, the territory of the Athenians, had an approximately equal number of inhabitants. Of the 300,000 thus accounted for, about one third was servile and one sixth foreign. The free and franchised population made up one half of the total, and yielded about 50,000 males of military age.
The empire of the Athenians consisted of five provinces, the Thracian, Hellespontine, Insular, Ionian, and Carian, with a total population of perhaps, 2,000,000. It formed a complex of islands, peninsulas, and estuaries, the most remote extremities of which were distant two hundred or two hundred and fifty miles from Athens. The highways of this empire were the land-locked channels and lakes which make up the Ægean Archipelago. Their greatest length in normal circumstances was a continuous voyage of about eight days. On the other hand, no land way of more than a single day's march need be traversed by an Athenian expedition aimed at any of its subject cities. Without the control of the sea the empire was, accordingly, unthinkable. This absent, the district fell at once into more than four hundred fragments, the thousand "cities" from which, according to the comedian Aristophanes, the Athenians gathered tribute.
The Athenian sphere of naval operations and of political and commercial interests reached far beyond the frontiers of the empire. It included points like Sicily, Egypt, Phœnicia, and the Euxine, distant over six hundred miles from the Piræus. An Athenian fleet might thus require the best part of a month to reach its destination. The world which had to take careful account of the Athenian naval power in all its political and military calculations, the world which Athens under Pericles sought to dominate, must have had a population of over 20,000,000.
If, then, we take into account the ratio of dominant, subject, and foreign elements, and also the time consumed in reaching with ships, orders, or explanations, the outer limits of authority, the magnitude of Athens's imperial undertaking will stand comparison with that of England in modern times.