70 HISTORY OF GREECE. is included Thebes, but not Thespi^ or Platsea. The ThessaKans, especially, not only submitted, but manifested active zeal and rendered much service in the cause of Xerxes, under the stim- ulus of the Aleuadae, whose party now became predominant : they were probably indignant at the hasty retreat of those who had come to defend them.^ Had the Greeks been able to maintain the passes of Olympus and Ossa, all this northern fraction might probably have been induced to partake in the resistance instead of becoming auxil- iaries to the invader. During the six weeks or two months which elapsed between the retreat of the Greeks from Tempe and the arrival of Xerxes at Therma, no new plan of defence appears to have been fonned ; for it was not until that arrival became known at the Isthmus that the Greek army and fleet made its forward movement to occupy Thermopylae and Ar temisium.2 CHAPTER XL. BATTLES OF THEE5I0PYLiE AND AETEMISIUM. It was while the northerly states of Greece were thus succes- sively falling off from the common cause, that the deputies as- sembled at the Isthmus took among themselves the solemn engagement, in the event of success, to inflict upon these recusant brethren condign punishment, — to tithe them in property, and perhaps to consecrate a tenth of their persons, for the profit of the Delphian god. Exception was to be made in favor of those states which had been driven to yield by irresistible necessity .2 Such a vow seemed at that moment little likely to be executed it was the manifestation of a determined feeling binding together ' Herodot. vii, 131, 132, 174. ^ Herod ot. vii, 177 3 Herodot. vii, 132 ; Diodor. xi, 3.
