 He had persuaded the Athenians and other Greeks that he and his army was heading for Halus, but it seems certain that he also sent other units straight to Thermopylae.Thus, when he swore oaths to the Athenian assembly in Pherae, his troops were already very close to Thermopylae; by the time the Athenian ambassadors arrived home (9 July), Philip was already in possession of the pass.By delaying the oaths, and making what was effectively a feint against Halus, he prevented the Athenians from seeing their imminent danger, and from having time to try to garrison Thermopylae.