Since the time of Homer, the Greeks have called themselves Hellenes (Έλληνες), though they have been known by a number of different names throughout history. The soldiers that fell at Thermopylae did so as the last protectors of Hellas. Homer, Herodotus and the later Greek authors locate the first usages of the word "Hellenes" as an ethnic name-umbrella under which the Achaians and the rest of the Greek allies sailed for the city state of Troy under Agamemnon's leadership, although up to that point "Hellas" (Greek: Eλλάς) and "Hellenes" was the name of the tribe (also called "Myrmidones") settled in Thessalic Phthia having Achilles as their leader.Alexander the Great is the first leader who officially uses the terms Hellas and Panhellenic League (league of all Greek tribes except for the Lacedaemonians) when he began his military campaign against the Persian rulers of the Greek city-states of Asia Minor (Ionia) to revenge their ancestors.