masses of troops, differing from each other in their equipment and methods of fighting, in disposition and in language, formed a herd of men rather than an army.  They had no cohesion or confidence in themselves, and their leaders, unaccustomed to command such enormous numbers, suffered themselves to be led rather than exercise authority as guides.  Any good qualities the troops may have possessed were neutralised by lack of unity in their methods of action, and their actual faults exaggerated this defect, so that, in spite of their splendid powers of endurance and their courage under every ordeal, they ran the risk of finding themselves in a state of hopeless inferiority when called upon to meet armies very much smaller, but composed of homogenous elements, all animated with the same spirit and drilled in the same school.

By continual conquests, the Persians were now reduced to only two outlets for their energies, in two opposite directions—­in the east towards India, in the west towards Greece.  Everywhere else their advance was arrested by the sea or other obstacles almost as impassable to their heavily armed battalions:  to the north the empire was bounded by the Black Sea, the Caucasus, the Caspian Sea, and the Siberian steppes; to the south, by the Indian Ocean, the sandy table-land of Arabia, and the African deserts.  At one moment, about 512 B.C., it is possible that they pushed forward towards the east.*

* India is not referred to in the Behistun Inscription, but is mentioned in one of the Inscriptions of Persepolis, and in that of Nakhsh-i-Rustem.  The campaign in which it was subjugated must be placed about 512 B.C.

[Illustration:  192.jpg FUNERAL OFFERINGS.]

From the Iranian plateau they beheld from afar the immense plain of the Hapta Hindu (or the Punjab).  Darius invaded this territory, and made himself master of extensive districts which he formed into a new satrapy, that of India, but subsequently, renouncing all idea of pushing eastward as far as the Granges, he turned his steps towards the southeast.  A fleet, constructed at Peukela and placed under the command of a Greek admiral, Scylax of Caryanda, descended the Indus by order of the king;* subjugating the tribes who dwelt along the banks as he advanced, Scylax at length reached the ocean, on which he ventured forth, undismayed by the tides, and proceeded in a westerly direction, exploring, in less than thirty months, the shores of Gedrosia and Arabia.

* Scylax published an account of his voyage which was still extant in the time of Aristotle.  Hugo Berger questions the authenticity of the circumnavigation of Arabia, as that of the circumnavigation of Africa under Necho.

Once on the threshold of India, the Persians saw open before them a brilliant and lucrative career:  the circumstances which prevented them from following up this preliminary success are unknown—­perhaps the first developments of nascent Buddhism deterred