Despite this appeal on the part of the Aleuadæ, the Thessalians as a body had at first no intention to medize. They disapproved of the action of this family; and, before the Persians had crossed the Hellespont, they sent a strongly worded appeal to the council of the Greeks assembled at the Isthmus to help them with a large force to defend the passage of Olympus: otherwise, they said, they must of necessity yield to the barbarian. The appeal did not remain without its effect. The Greeks determined to send an army to guard the Vale of Tempe. Ten thousand heavy-armed troops were despatched by sea up the Euripus, and, after landing at Halos on the west shore of the Pagasætic Gulf, marched to Tempe.[101] The despatching of these troops by sea has been taken to indicate that the Greeks mistrusted the attitude of the Bœotians. It is, perhaps, possible to attach too much importance to the symbolical submission of the Northern States of Greece. The general course of events would seem to indicate that one of two things was the case at this time. It may have been that the heralds had not yet visited these States to receive their submission when the expedition to Tempe took place—a quite possible contingency when it is borne in mind that these events are dated by Herodotus as occurring at a time when the Persian had not yet crossed into Europe, whereas the heralds did not meet Xerxes until he got to Therma. Or it may have been that, if such submission had been made, it had been made with the mental reservation of the intention to take part with the rest of Greece, provided the Southern States showed a disposition to strike a blow in defence of the North.[102] #EXPEDITION TO THESSALY.# The Bœotian attitude at the time of Thermopylæ, as related by Herodotus, is so extraordinary as to be incredible; and his account of the attitude of these Northern States at this time suggests the suspicion that the bitterness of feeling against them, which undoubtedly existed after Platæa, has been antedated by him, and has led to the growth of a story discreditable to them, relating to the time immediately previous to the actual invasion. It is not difficult to see that the Greek States of the South, by the selfishness of their policy, made it necessary for the States of the North to seek their own salvation by an attitude which, though on the face of it unpatriotic, was forced on them by the situation. Such is the conclusion which may be drawn from Herodotus’ narrative of the events of this period. It is a tale undoubtedly coloured by the bitterness of the feeling subsequently displayed to those Greeks who were represented as having betrayed the Greek national cause. It may be, after all, that the account of the matter in Diodorus, which is more explicit, is also more true. If he is to be believed, neither Locris nor Bœotia nor the Thessalians proper medized until the retreat from Tempe left North Greece deserted for the time being.