[111] It would, I reckon, be possible for a traveller to go from one plain to the other by this route without attaining a height much over a thousand feet.

[112] It may be well to adduce one or two striking instances of this, apart from the one at present under consideration:⁠—

  1. Circ. 350 B.C., Thermopylæ was the great obstacle to Philip’s advance south. His energies were centred in getting hold of the pass. He never attempted an assault upon it, but finally got hold of it by bribing Phalæcus, the Phocian condottiere. He then left a garrison at Nicæa near Thermopylæ (Dem. ad Ep. Phil. 4). There must have been some supreme objection from a military point of view to the Asopos pass, since Philip, who can hardly be suspected of military incapacity, never tried to turn Thermopylæ by using it. He was not pressed for time. He patiently allowed years to elapse before he got hold of Thermopylæ. Thermopylæ was all-valuable to him, and, what is more striking, absolutely necessary, in his opinion, for an advance southwards. (Vide Hogarth, “Philip and Alexander”).
  2. In 279 B.C. (Pausanias, x. 20) Brennus, with more than 150,000 Gauls, invaded Greece. The object of the expedition was plunder and nothing else. If he could have got past Thermopylæ that object would have been attained. With such numbers he could have done what he liked, especially if, after getting through the Asopos defile, he had, before going south, turned Thermopylæ by way of Hyampolis and forced the Greeks to evacuate that pass. Pausanias, who seems to have ample information as to the details of this Celtic raid, gives the following list of the defending force:⁠—
  3. Bœotians, 10,000 infantry, 500 cavalry; Phocians, 3000 infantry, 500 cavalry; Megareans, 4000 infantry; Ætolians, 7000 infantry, with numerous light armed, and cavalry; Athenians, 1000 infantry, 500 cavalry, with numerous triremes; Mercenaries from Macedonia and Asia, 1000 infantry.
  4. The total cannot have been far short of 25,000 men.
  5. The force was so large that the commanders were enabled not merely to provide for the defence of the pass itself, but were also able to send out cavalry and light armed to dispute the passage of the Spercheios, a move which Brennus, who was, as Pausanias remarks, “not altogether wanting in understanding, nor, for a barbarian, without a certain amount of experience in devising stratagems,” frustrated by sending a number of his men across the bar at the river mouth. On this the Greek advanced guard retreated to the pass. Brennus then had bridges thrown across the river, and attacked Heraklea. The Heraklea of that date was probably situated on the mountain immediately west of the mouth of the Asopos ravine, on a site now known as Sideroporto. He did not take the place; and Pausanias adds in reference to this, that Heraklea was to him “a matter of lesser moment: he considered the main point to be to drive out of the pass those who were in occupation of it, and to make good his passage into Greece south of Thermopylæ.”
  6. It is of course manifest that such a passage as the Asopos ravine would be easily defensible, and the Herakleots may have blocked it. There is no question that, had it been passable, Brennus might have used it. The striking fact is that he did not use it, but spent his strength on a terrific failure at Thermopylæ.
  7. In 224 (vide Polyb. xi. 52) Antigonus, wishing to get to the Isthmus, marched with his army by way of Eubœa. “He took this route,” says Polybius, “because the Ætolians, after trying other expedients for preventing Antigonus bringing this aid, now forbade his marching south of Thermopylæ with an army, threatening that, if he did, they would offer armed opposition to his passage.”
  8. It is to be noted that, as at the time of Brennus’ assault, the defenders of the pass were also in possession of Heraklea.
  9. In B.C. 208 (vide Polyb. x. 41) the Ætolians, seeking to prevent the passage of Philip of Macedon southwards to aid his allies, “secure the pass of Thermopylæ with trenches and stockades and a formidable garrison, satisfied that they would then shut out Philip, and entirely prevent him from coming to the assistance of his allies south of the pass.”
  10. In this case also (vide chap. 42) the Ætolians were in possession of Heraklea.
  11. In a passage already quoted, Livy (xxxvi. 15) is most emphatic in his statement that the only practicable military route by Œta is that through Thermopylæ. He is describing the attack of the Romans under Acilius Glabrio upon the troops of Antiochus who were defending the pass, and it is again reported that the allies of the defenders were in possession of Heraklea.

We are now in possession of practically all the data which can be obtained from the ancient historians with regard to the exact significance of the Asopos ravine, and the route through it. It must of course be borne in mind that the information of the historian Livy with regard to the topography of the Thermopylæ region was second-hand; but yet, in spite of that, there is a certain consistency about the evidence which enables us to form highly probable conclusions with regard to the exact value of this factor in the strategical geography of the region.

It seems to me to have been a recognized principle in later times that an effective defence of Œta included the occupation of Heraklea as well as of Thermopylæ, and the only conceivable reason for the existence of such a view is that Heraklea commanded the passage of the Asopos ravine.

The site of the Heraklea of this period is to be sought, I venture to think, at the place called Sideroporto, where there are large remains of a strongly fortified town. It is high on the slope of Œta, in an exceedingly inaccessible position, in the angle, as it were, between the Asopos ravine and the line of the Trachinian cliffs.

A local tradition, probably of recent date, and due, like so many traditions of modern Greece, to the visit of some inquirer whom the natives regarded as an authority, attaches the name of Heraklea to certain ruins which stand on the summit of a remarkable flat-topped mountain in the valley at the head of the Asopos ravine, to which reference has been already made, between the plains of Malis and Doris. It is infinitely more probable, however, that this was the stronghold of those Œteans whom Thucydides mentions.

The site is more than two hours distant from the nearest point of the Malian plain, at the outlet of the Asopos ravine.

[113] Cp. H. vii. 175, ad fin.

[114] It has been criticized in modern times on strategical principles (e.g. by Delbrück), for which a universality of truth has been claimed. It is said that, given two adversaries of equal strength, that one places himself at a disadvantage who attempts to defend the passage of a range of mountains. It is manifest that the assailant can concentrate his efforts on the forcing of one passage, whereas the defender has to distribute his defence among all the practicable passages of the chain. In the particular case of Mount Œta it is urged that there was, besides Thermopylæ, at least one practicable passage, and this is stated to have followed the modern road from Malis into Doris; which passes over the low part of the chain immediately east of the Asopos ravine.