(Περδίκκας), king of Macedonia, was the second son of Amyntas II., by his wife Eurydice. He was still very young when the assassination of his brother Alexander II., by Ptolemy of Aiorus, caused the crown of Macedonia to devolve by hereditary right upon him. Ptolemy, however, assumed the government as regent during the minority of Perdiccas, with the concurrence of Eurydice. But the appearance of a new competitor for the throne, Pausanias, soon compelled both Eurydice and her two sons, Perdiccas and Philip, to have recourse to the assistance of the Athenian general Iphicrates, who drove out the usurper, and re-established Perdiccas upon the throne. Ptolemy seems to have been reinstated in his office of regent or guardian of the young king, under which name he virtually enjoyed the sovereign power, until at length Perdiccas caused him to be put to death, and took the government into his own hands, B. C. 364. (Just. 7.4, 5; Aesch. de Fals. Leg. §§ 28-31, ed. Bekk.; Diod. 15.77, 16.2 ; Syncell. p. 263; Flathe, Gesch. Mlacedon. vol. i. p. 39-40; Thirlwall's Greece, vol. v. p. 162-164.) Of the subsequent reign of Perdiccas we have very Little information. We learn only that he was at one time engaged in hostilities with Athens on account of Amphipolis (Aesch. l.c. §§ 32-33), and that he was distinguished for his patronage of men of letters. Among these we are told that Euphraeus, a disciple of Plato, rose to so high a place in his favour, as completely to govern the young king, and exclude from his society all but philosophers and geometers. (Carystius, apud Atthen. xi. pp. 506, e. 508, d.) Perdiccas fell in battle against the Illyrians after a reign of five years, B. C. 359. (Diod. 16.2. The statement of Just. 7.5, that he was killed by Ptolemy of Alorus is clearly erroneous. See, however. Curt. 6.11.26.) He left an infant son, Amyntas, who was, however, excluded from the throne by his uncle Philip. [AMYNTAS, No. 3.]