The occupant of Tomb III, the Prince's Tomb, is Philip IV!

[antipater]

Occording to a concept presented by me, the occupant of Tomb III, the Prince's Tomb, is Philip IV, king of Macedonia. He was the oldest son of Kassander, who died in 297. Philip IV was on the Macedonian throne only few months when he died in 297 at an age of about 14 years.
http://www.macedonia.se/en/Load/30/vergina_tomb_3/

[Nicator]

We can never really know who was in that tumulus. But it would be interesting to be a bug on the wall when the thing was constructed.

[Nicator]

There are several notable youtube vids on that undertaking worth a gander as well.