Perdiccas III of Macedon in Wikipedia
Perdiccas III (Greek: Περδίκκας Γ`) was king of Macedonia from 368 to 359 BC, succeeding his brother Alexander II.
Son of Amyntas III and Eurydice, he was underage when Alexander II was killed by Ptolemy of Aloros, who then ruled as regent. In 365, Perdiccas killed Ptolemy and assumed government.
Of the 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 , 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.
He also served as Theorodokos in the Epidaurian Panhellenic games of about 365 BC.
He tried to reconquer upper Macedonia from the Illyrian Bardylis, but the expedition ended in disaster, with the king killed.
Perdiccas was succeeded by his infant son, Amyntas IV. The throne was soon usurped by Perdiccas' younger brother Philip II.
Perdiccas in Harpers Dictionary of Classical Antiquities (1898)
Perdiccas III., king of Macedonia, B.C. 364-359, was the second son of Amyntas II., by his wife Eurydicé. On the assassination of his brother Alexander II., by Ptolemy of Alorus, B.C. 367, the crown of Macedonia devolved upon him by hereditary right, but Ptolemy virtually enjoyed the sovereign power as guardian of Perdiccas till B.C. 364, when the latter caused Ptolemy to be put to death, and took the government into his own hands (Just.vii. 4). Of the 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, and that he was distinguished for his patronage of men of letters. He fell in battle against the Illyrians in B.C. 359.