The Isthmus of Corinth was west of Salamis, some fifteen miles, across the bay. The army, in retreating from Athens toward the isthmus, would have necessarily to pass round the bay in a course somewhat circuitous, while the fleet, in following them, would pass in a direct line across it. The geographical relations of these places, a knowledge of which is necessary to a full understanding of the operations of the Greek and Persian forces, will be distinctly seen by comparing the above description with the map placed at the commencement of the fifth chapter. It had been the policy of the Greeks to keep the fleet and army as much as possible together, and thus, during the time in which the troops were attempting a concentration at Thermopylae, the ships made their rendezvous in the Artemisian Strait or Channel, directly opposite to that point of the coast. There they fought, maintaining their position desperately, day after day, as long as Leonidas and his Spartans held their ground on the shore. Their sudden disappearance from those waters, by which the Persians had been so much surprised, was caused by their having received intelligence that the pass had been carried and Leonidas destroyed. They knew then that Athens would be the next point of resistance by the land forces. They therefore fell back to Salamis, or, rather, to the bay lying between Salamis and the Athenian shore, that being the nearest position that they could take to support the operations of the army in their attempts to defend the capital. When, however, the tidings came to them that Athens had fallen, and that what remained of the army had retreated to the isthmus, the question at once arose whether the fleet should retreat too, across the bay, to the isthmus shore, with a view to co-operate more fully with the army in the new position which the latter had taken, or whether it should remain where it was, and defend itself as it best could against the Persian squadrons which would soon be drawing near. The commanders of the fleet held a consultation to consider this question. In this consultation the Athenian and the Corinthian leaders took different views. In fact, they were very near coming into open collision. Such a difference of opinion, considering the circumstances of the case, was not at all surprising. It might, indeed, have naturally been expected to arise, from the relative situation of the two cities, in respect to the danger which threatened them. If the Greek fleet were to withdraw from Salamis to the isthmus, it might be in a better position to defend Corinth, but it would, by such a movement, be withdrawing from the Athenian territories, and abandoning what remained in Attica wholly to the conqueror. The Athenians were, therefore, in favor of maintaining the position at Salamis, while the Corinthians were disposed to retire to the shores of the isthmus, and co-operate with the army there.