In like manner the habits of nomad nations necessarily causes such armaments to consist altogether or principally of cavalry. The first was the case with the Mongols; the last with the Persians. As the first-mentioned practice retards, so does this greatly accelerate the march of their armies. The limited nature of their wants enables them, when occasion requires, to dispense with any baggage, and the history of the Mongols affords examples of the inconceivable speed with which such armies have accomplished lengthened marches which would have driven a European army to despair.
Costume of a Persian King
(After Du Sommerard)
These are the fundamental points to be observed with regard to the military system of nomad nations in general and the Persians in particular; but as their civil constitution became gradually developed, so did their military institutions undergo at all events considerable modifications, although they never attained the perfection which marks those of Europe. The example of the Turkish empire continues to show with what difficulty an Asiatic, who is always half a nomad, can be inured to discipline. As this is the offspring of a sense of honour and love of country, so, on the other hand, despotism is the parent of license and brutality, which may indeed display their energies in furious onsets, but not in deeds of cool daring like those of Europeans.
A dominion acquired by conquest can only be maintained by standing armies, and we cannot, therefore, be surprised to find the provinces of Persia constantly occupied by great masses of men, destined to keep them in subjection, as well as to defend them against a foreign invader. Immediately upon the completion of their conquests such forces were suffered to remain in the provinces, supported not by the king but by the conquered. Examples especially occur in the frontier states, in Asia Minor, Egypt, and others, which were especially exposed to assaults from without, or where an insurrection was most to be apprehended. Asia Minor, however, from the commencement of the wars with Greece, became the principal depot for the forces of Persia; it was filled with considerable bodies of men which could be readily drawn together when occasion required, and thus Alexander, on invading it, found there troops drawn together to oppose him on the banks of the Granicus.
In the most flourishing epoch of their history the military system of the Persians was as follows. In every province were kept up two descriptions of forces, those which occupied the open country, and those which kept possession of the cities, as garrisons. These were distinct, and commanded by different generals. Of the first description of forces it was clearly defined how many, and of what class, were to be maintained in each province. The principal strength consisted in cavalry, but there were also bowmen, slingers, and heavy-armed infantry. The care of keeping up the full numbers of these forces was committed to their successive commanders, and they were supported, both as respected food and money, by the revenues of the provinces, and as these were paid into the treasury of the satrap, the latter had to provide for the pay of the soldiery. The commanders, however, of the forces were not subject to the governors, unless by special appointment. On the other hand, they appear to have been immediately dependent on the king, having been appointed by him and deposed at his pleasure, and a catalogue of such offices remaining in his hands. The annual reviews of the forces also, which were extended to all the empire, were not usually held by the satraps, but in the neighbourhood of the capitals, by the king himself, and in remote provinces by persons deputed by him to hold them in his name. Great exactness was exercised on these occasions, and according to the good or bad condition of the forces their commanders were applauded and rewarded with presents, or deprived of their rank, or visited with arbitrary punishments.
To these arrangements was added another, the subdivision of the empire into certain military cantons, independent of the civil administration; formed with a reference to the muster-places of the troops. In this manner the forces stationed in a particular province were always collected at one point, from which the canton derived its appellation. Mention occurs of those in Asia Minor, and as the above institutions extended to the whole of the empire, and reviews were held in every province, it is to be supposed that this custom also was universal. Herodotus expressly mentions the cantons on this side the Halys, and consequently we must conclude the same to have prevailed on the other side. Of the cantons in Asia Minor, Xenophon particularises that of which the muster-place was the plain of Castolus, as that of Thymbra was for the army of Syria; Herodotus also mentions the Aleius Campus in Cilicia.