During the first years of his reign, Evagoras doubtless paid his tribute regularly, and took no steps calculated to offend the Persian king. But as his power increased, his ambition increased also. We find him towards the year 390 B.C., engaged in a struggle not merely with the Persian king, but with Amathus and Kitium in his own island, and with the great Phœnician cities on the mainland. By what steps, or at what precise period, this war began, we cannot determine. At the time of the battle of Knidus (394 B.C.) Evagoras had not only paid his tribute, but was mainly instrumental in getting the Persian fleet placed under Konon to act against the Lacedæmonians, himself serving aboard.[48] It was in fact (if we may believe Isokrates) to the extraordinary energy, ability, and power, displayed by him on that occasion in the service of Artaxerxes himself, that the jealousy and alarm of the latter against him are to be ascribed. Without any provocation, and at the very moment when he was profiting by the zealous services of Evagoras, the Great King treacherously began to manœuvre against him, and forced him into the war in self-defence.[49] Evagoras accepted the challenge, in spite of the disparity of strength, with such courage and efficiency, that he at first gained marked successes. Seconded by his son Pnytagoras, he not only worsted and humbled Amathus, Kitium, and Soli, which cities, under the prince Agyris, adhered to Artaxerxes,—but also equipped a large fleet, attacked the Phœnicians on the mainland with so much vigor as even to take the great city of Tyre; prevailing, moreover, upon some of the Kilikian towns to declare against the Persians.[50] He received powerful aid from Akoris, the native and independent king in Egypt, as well as from Chabrias and the force sent out by the Athenians.[51] Beginning apparently about 390 B.C., the war against Evagoras lasted something more than ten years, costing the Persians great efforts and an immense expenditure of money. Twice did Athens send a squadron to his assistance, from gratitude for his long protection to Konon and his energetic efforts before and in the battle of Knidus,—though she thereby ran every risk of making the Persians her enemies. [48] This much appears even from the meagre abstract of Ktesias, given by Photius (Ktesiæ Persica, c. 63, p. 80, ed. Bähr). Both Ktesias and Theopompus (Fr. iii, ed. Wichers, and ed. Didot) recounted the causes which brought about the war between the Persian king and Evagoras. [49] Isokrates, Or. ix, (Evag.) s. 71, 73, 74. πρὸς δὲ τοῦτον (Evagoras) οὕτως ἐκ πολλοῦ περιδεῶς ἔσχε (Artaxerxes), ~ὥστε μεταξὺ πάσχων εὖ~, πολεμεῖν πρὸς αὐτὸν ἐπεχείρησε, δίκαια μὲν οὐ ποιῶν, etc.—ἐπειδὴ ~ἠναγκάσθη πολεμεῖν~ (_i. e._ Evagoras). [50] Isokr. Or. ix, (Evag.) s. 75, 76; Diodor. xiv, 98; Ephorus, Frag. 134, ed. Didot. [51] Cornelius Nepos, Chabrias, c. 2; Demosthenes adv. Leptinem, p. 479, s. 84.