The difficulties of this pass are such that it was rarely used for military purposes, and it seems to have played no part whatever in the operations of 479.
The second pass is that which the road from Platæa to Megara formerly traversed. It crosses Kithæron a little more than a mile eastward of Platæa, entering a deep valley which runs into the chain from the north, and ascending steeply from the head of the valley to the summit of a col in the ridge. Its character forbids the supposition that it can ever have been used for wheeled vehicles, and its importance must have been mainly due to the fact that it is the only one of this series of passes, with the exception of the track by Ægosthena, by which land communication between Northern Greece and the Peloponnese could be maintained without entering Attic territory. The road south of it, towards Megara, traverses the troublesome hill region of the Northern Megarid.[182] The fact that Platæa practically commanded the northern end of this pass rendered the town one of the most important strategic positions in Greece, both in the fifth and in the fourth centuries. It will be hereafter seen that this pass must have played an important part in the operations of the Greek army at Platæa.
The third pass is one by which the road from Platæa to Athens crossed the range. It is little more than a mile to the east of that last mentioned. Remains of the road are visible on the north side, entering a somewhat broad valley running into the hills. It must have always been an easy pass, and the ancient wheel-ruts worn in the rock show that it was used by wheeled vehicles.[183] PASSES BETWEEN ATTICA AND BŒOTIA. The road, after traversing it, turned east, and joined, near Eleutheræ, the road from Thebes to Eleusis by way of the pass of Dryoskephalæ. This pass also played an important part in the operations at Platæa.
The fourth pass was well known under its Attic name of Dryoskephalæ, and though not traversed by the direct road between Thebes and Athens, must have been largely used by those going from one place to the other, owing to the route by way of it being more easy than the direct road by Phyle. From the Bœotian side, near the site of the ancient Erythræ, the ascent is steep; it must have always been necessary to make it by a series of zigzags. The summit once reached, the descent is gradual, down a long stream-valley which abuts on a small plain of Attica beneath the fortress of Eleutheræ. As a pass, it was probably always more difficult than that on the Platæa-Athens road, but as the route from Thebes through it was more direct, it became the most used of the passes of Kithæron, and seems to have been the only one which had a special name in ancient times. The road through it was continued southward through a not very difficult country, as country goes in Greece, to the Thriasian plain and Eleusis, passing by or very near the fortress of Œne, whose importance must have been due to its position with reference to this road. Near Eleusis it joined the Sacred Way to Athens. Of the importance of this pass at the time of the battle of Platæa it is hardly necessary to speak.
The fifth of the series of passes is that on the direct road between Thebes and Athens. After ascending from the Bœotian plain to the plateau of Panakton, it traverses the upland pastures of that region, and enters a difficult country, where it was commanded by the important Attic fortress of Phyle. Thence it reaches the head of the Athenian plain. Mardonius might certainly have made use of this route for his retreat. He preferred, however, the more roundabout way through the sixth pass. It may have been, on the whole, an easier route. Furthermore, Mardonius, who seems to have been more apprehensive than he need at this moment have been that his retreat might be cut off, evidently thought that the route furthest from the Greek lines of advance would be safest.
The sixth pass leads from the plain of Athens into the lower basin of the Asopos. It was commanded near its summit by that fortress of Dekeleia which was destined to become so famous in the latter part of the Peloponnesian war. After passing Dekeleia, it was possible, instead of continuing along the road due north, to diverge to the left and follow a stream-valley to Tanagra. From Tanagra there must always have been a good, though not absolutely direct, road to Thebes, and also an easy passage up the Asopos valley.
H. ix. 14.
Herodotus, after describing Mardonius’ preparations for leaving Athens, says that when already on his way it was reported to him that a body of a thousand Lacedæmonians had been pushed forward to Megara. On hearing this, he wheeled about, and led his army as far as Megara, while his cavalry overran the whole of the Megarid. Herodotus’ intention in mentioning the incident is made sufficiently clear by the words which follow: H. ix. 14, ad fin. “This is the furthest point west in Europe which the Persian army reached.” Paus. i. 44, 4. It is to this expedition that a tradition mentioned by Pausanias must be referred—a tradition which preserved the record of the advance of the Medes to Pagæ.
There is no reason to doubt that the Persian raid into the Megarid is an historical fact, recorded by Herodotus and preserved in this chance tradition. It is not, however, at all likely that it was made by the whole Persian army, or that it was made at the time Herodotus mentions. His object in relating the story is plainly indicated, and in his desire to make his main point, he has probably not been over careful as to exactness in date.
If Mardonius wished, as is represented by the historian, to secure his safe passage to Bœotia, he would hardly have turned back with all his force. Had he done so, his natural line of withdrawal would have been by Dryoskephalæ. MARDONIS RETREATS TO BŒOTIA. The raid into Megara seems to have been a cavalry reconnaissance, whose object was to discover what the Greeks were doing at the Isthmus, and, moreover, it was probably made several days at least before the time indicated by Herodotus.