The Athenians, on learning the actual approach of the Persian forces, had sent a swift runner to Sparta to beg for help. The man reached Sparta, a distance of about one hundred and forty miles, in less than forty-eight hours ("on the second day" is the expression). The Spartans promised to come, but could not start, they said, till after the full moon, which was then five days off. The question then among the Athenian generals--there were ten in number and had each his day of command--was whether they should fight at once or wait for the Spartan contingent. The ten generals who shared the command of the army were equally divided in opinion. But Miltiades, the most distinguished of their number, was eager for instant action, and succeeded in winning over to his views Callimachus the Polemarch, with whom it lay, in case of an equal division, to give the casting vote. We shall see that he had good reasons for his action, and that his promptitude saved Athens; and, we may say, Greece. The centre of the Persian line of battle was held by the native Persians and Sacæ, these latter a tribe now represented by the Turcomans. Of the rest of the formation we are told nothing. Some cavalry they had, but it is not mentioned as taking any part in the battle. It has been conjectured that it had not been disembarked when the battle was fought. It would certainly have been difficult to get the horses on board again, and if any number of them had been captured, we should probably have heard something about it. The Athenian line was drawn up so as to be equal in length to the Persian. To effect this it was, of course, necessary to make it very thin in parts. This was the case in the centre, where there were but two or three files. No light armed soldiers, no archers, no cavalry were present. All were heavy armed men with a few slaves in attendance. The right wing was commanded by Callimachus; the Platæans were on the left.