Meat was a staple part of their diet, and ‘meat on the hoof’ was brought into the principal supply depots long before the army moved. At the same time great quantities of salted-down meat were stockpiled. The army, of course, as it moved across Asia Minor, and later into Greece, was expected to live off the land to a large extent, but Xerxes and his commissariat organisers did not make the great mistake of many later armies in assuming that so large a force could necessarily supply itself in this hand-to-mouth fashion. In Persia and the Greeks A. R. Burn quotes the description of Persian preparations for war by Theopompos of Chios. It is true that Theopompos was writing much later about an expedition against Egypt, but there is little reason to believe that Persian thoroughness had changed since the time of Xerxes. He records the 

tens of thousands of stand of arms, both Greek and oriental; vast herds of baggage animals and beasts for slaughter; bushels of condiments, and boxes and sacks, and bales of paper and all the other accessories. And there was so much salt meat of every kind, that it made heaps, so large that people approaching from a distance thought they were coming to a range of hills.

The reference to the bales of paper can only bring a wry smile to the face of anyone who has served in modern wars. Persia was nothing if not a bureaucratic state, and they had learned largely from the Egyptians, with their tradition of meticulous public records, that the organisation of a great country, and more especially an empire, required scribes and civil servants and departmental organisers. They were among the forerunners-in the large-scale use of paperwork - under which so much of the world groans today. (Byblos, one of the principal Phoenician cities, which came under the sway of Persia, was credited with having been the inventor of paper - made from papyrus. The word Bible (‘Book’) derives from Byblos.)

Especial provision was made in the way of stores for the army when it should have crossed into Greece. While in Asia Minor they might be expected to feed off the land to a great extent, since all of the area came under Persian rule. Such could not be expected in Greece itself once the army was south of the pro-Persian north. The River Strymon, which empties into the sea to the north of Mount Athos, was bridged for the passage of the army, and in several parts of this region of Thrace great provision dumps were established. The largest of these was at the White Cape on the Thracian coast and another was at the mouth of the Strymon near the new bridge. Yet others were sited to the south, in parts of Macedonia.

So much that Herodotus and later Greek historians considered as evidence of the megalomania of Xerxes and the hubris of a typical Oriental tyrant was no more than evidence of forethought, excellent logistics, and planning superiority over the Greeks of the period. The small Greek city-states could not understand what the organisation of a great empire and the movement of many thousands of men entailed: they themselves thought in terms of hundreds or at the most a few thousands. It would be well over a century until a Greece, unified under Alexander the Great, would have to tackle the problems of Empire. The principal source of amazement, not untinged with some reluctant admiration, was the great bridge of boats which Xerxes ordered to be constructed across the Hellespont at the narrows between Abydos on the Asian side to a point near Sestos on the European side: a distance of about seven furlongs or 1400 yards.

There were two bridges supported on 674 biremes and triremes which were used to form the floating platforms upon which the carriageway itself was laid. There were 360 vessels on the side towards the Black Sea and 314 on the southern section. One of these was allocated to the Egyptian workmen and the other to the Phoenicians. One may suspect that the Phoenicians built a better bridge (admirable though the Egyptians were as architects, they were not so distinguished a seafaring people as the masters of Tyre and Sidon). Nevertheless a storm of ‘great violence’ smashed both bridges shortly after they had been completed. Xerxes’ reaction was, in accordance with the Greek view of Herodotus, that of a maddened tyrant who expects that even the winds and the waves will respect his wishes. He gave orders that the Hellespont should be given three hundred lashes, that a pair of fetters be thrown into the sea, and even that it should be branded like a common criminal. Herodotus, like all Greeks (who made their living so largely from the sea and to whom the sea-god Poseidon was a deity always to be placated), regarded this not only as a barbarous, but indeed a maniacal act. ‘You salt and bitter current,’ Xerxes is said to have ordered the men who wielded the whips to say, cyour master inflicts this punishment upon you for doing harm to him, who never harmed you. Nevertheless Xerxes the King will cross you with or without your permission.