Philip III - ΒΑΣΙΛΕΩΣ of Macedon from 323 BC to 317 BC
Philip III reigned as king of Macedonia from after 11 June 323 BC until his death. He was a son of Philip II by Philinna of Larissa, and thus an elder half-brother of Alexander the Great.

Originally named Arrhidaeus, Philip III was the closest living relative to Alexander III upon his death - but due to mental disabilities was unfit to rule. Followng a power struggle, it was decided that he would reign as Philip III, but would not rule - this was to be the responsibility of a regent, Perdiccas.

Philip III would formally reign alongside his infant nephew Alexander IV until his death on 25 December 317 BC, where he was executed by his step-mother Olympias, the mother of Alexander III, during one of the many conflicts between the diadochi.
Philip III
King Philip III of Macedonia

(1) Alexander III | Philip III 322-319 BC
Obverse: head of young Heracles in lion's skin right
Reverse: Zeus enthroned left, holding eagle and scepter, barleycorn under throne, spear-spike right AΛEΞANΔPOY
Ref: Price 1751
(2) Philip III c. 323 - 319 BC
Obverse: Head of Herakles right, wearing Nemean lion scalp headdress
Reverse: ΦIΛIΠΠOY / Zeus seated left on throne without back, nude to waist, himation around hips and legs, right leg forward, feet on footstool, eagle in extended right hand, long scepter vertical behind in left hand, monogram below throne
Ref: Price P57, Müller Alexander P89a, S...
(3) Philip II | Philip III 323-315 BC
Obverse: head of Apollo wearing tainia right
Reverse: horseman riding right; ΦIΛIΠΠOY, M in wreath
Ref: Le Rider pl. 45, 33; SNG ANS 625-7;...