When transferred from Thebes to the subordinate government of a district in Macedonia under his elder brother Perdikkas, Philip organized a military force; and in so doing had the opportunity of applying to practice, though at first on a limited scale, the lessons learnt from the illustrious Thebans. He was thus at the head of troops belonging to and organized by himself—when the unexpected death of Perdikkas opened to him the prospect of succeeding to the throne. But it was a prospect full of doubt and hazard. Perdikkas had left an infant son; there existed, moreover, three princes, Archelaus, Aridæus, and Menelaus,[433] sons of Amyntas by another wife or mistress Gygæa, and therefore half-brothers of Perdikkas and Philip: there were also two other pretenders to the crown—Pausanias (who had before aspired to the throne after the death of Amyntas), seconded by a Thracian prince—and Argæus, aided by the Athenians. To these dangers was to be added, attack from the neighboring barbaric nations, Illyrians, Pæonians, and Thracians—always ready[434] to assail and plunder Macedonia at every moment of intestine weakness. It would appear that Perdikkas, shortly before his death, had sustained a severe defeat, with the loss of four thousand men, from the Illyrians: his death followed, either from a wound then received, or by the machinations of his mother Eurydikê. Perhaps both the wound in battle and the assassination, may be real facts.[435] [433] Justin, vii. 4. Menelaus, the father of Amyntas and grandfather of Philip, is stated to have been an illegitimate son; while Amyntas himself is said to have been originally an attendant or slave of Æropus (Ælian, V. H. xii. 43). Our information respecting the relations of the successive kings, and pretenders to the throne, in Macedonia, is obscure and unsatisfactory. Justin (_l. c._) agrees with Ælian in calling the father of Amyntas Menelaus; but Dexippus (ap. Syncellum, p. 263) calls him Aridæus; while Diodorus (xiv. 92) calls him Tharraleus. [434] Justin, xxix. 1. [435] Diodor xvi. 2; Justin, vii. 5; Quint. Curt. vi. 48, 26. Philip at first assumed the government of the country as guardian of his young nephew Amyntas the son of Perdikkas. But the difficulties of the conjuncture were so formidable, that the Macedonians around constrained him to assume the crown.[436] Of his three half-brothers he put to death one, and was only prevented from killing the other two by their flight into exile; we shall find them hereafter at Olynthus. They had either found, or were thought likely to find, a party in Macedonia to sustain their pretensions to the crown.[437] [436] Justin, vii. 5. Amyntas lived through the reign of Philip, and was afterwards put to death by Alexander, on the charge of conspiracy. See Justin, xii 6; Quintus Curtius, vi. 34, 17; with the note of Mützell.