A careful study of all the examples leads to the conclusion that this globe and crescent, or cruciform, standard was the symbol of naval authority, the prototype in fact of the Admiral's flag. The name of this standard is not specifically stated, but there can be no doubt that it is the _semeion_ (σημεῖον [Greek: sêmeion]) frequently referred to by Greek authors in describing naval actions. That the _semeion_ was a solid object we know from the fact that it was raised aloft in giving signals[16]. There is evidence that _semeia_ were of various forms and that these forms were distinctive of the nationality of the ship. Of Artemisia, queen of Halicarnassus, who accompanied Xerxes in his expedition against Greece and fought on the Persian side at the Battle of Salamis (480 B.C.), Polyaenus, in his _Strategemata_, relates that she had two _semeia_, one of "barbarian" form, the other Greek. When she was pursuing a Greek ship she raised aloft the barbarian standard[17], but when fleeing before a Greek ship she raised the Greek standard, so that her pursuer took her ship for Greek and kept off from it. The "barbarian" standard used by Artemisia was probably the globe and crescent above referred to, for Sidon supplied Xerxes with the best of his ships, and it was in Sidonian ships that Xerxes himself was wont to embark[18]. It seems, on the other hand, probable that a cruciform standard was in common use by all the Greek states at an early period, for Polyaenus relates that Chabrias, the Athenian general, just before his action off Naxos in 376 with the Lacedaemonian fleet under Pollis, ordered his subordinate commanders to remove the _semeia_ from their ships and to keep in mind, in the ensuing conflict, that all ships bearing such signs were enemies[19]. The flag was evidently unknown to the early Greeks; it is never mentioned by Homer, and indeed there is no equivalent word in the language of the classical period, yet at the time when we first meet with the standard on the Phoenician coins flags were in common use by the Chinese. The Chinese classics on the art of war known as the Sun Tzu and Wu Tzu, written in the fifth century B.C., make frequent reference to them. They played a very important part in marshalling the army and inspiriting the soldiers, and the correct moment to strike the enemy was judged by the disorder of their flags. According to Wu, the Chinese flags contained various animal emblems.