Drachm - Philip III Arrhidaios Sardes

Philip III Arrhidaios was Alexander's half-brother — intellectually disabled, likely kept deliberately marginalized during Alexander's lifetime, and elevated to the throne in 323 BC largely because the Macedonian infantry needed a king they could name while the generals negotiated. He never ruled in any meaningful sense. Antipater, then Polyperchias, then Olympias controlled him in sequence. Olympias had him executed in 317 BC.

The Sardes mint continued Alexander-type coinage under his name with minimal interruption, which is why Price assigns these a distinct prefix rather than folding them into the main Alexander sequence.