On the fifth day after the Persian arrival at Thermopylae, which would become the first day of the battle, Xerxes finally resolved to attack the Greeks. First of all, he sent Medes and Cissians against the Greeks, to take them prisoner and bring them before him. They soon found themselves launching a frontal assault on the Greek position. The Greeks fought in front of the Phocian wall, at the narrowest part of the pass. Details of the tactics are scant; Diodorus says "the men stood shoulder to shoulder" and the Greeks were "superior in valor and in the great size of their shields."