Alexander the Great travelled to the Prophet of Siwa and was told he was “…the son of a God…”; every reference I’ve found uniformly names that god as Zeus – King of the Gods. HOWEVER, I seem to recall that Michael Wood’s doco (don’t quote me, it’s been a while, ok?) named that god as Apollo. Considering the “bright” nature of Apollo AND the “volatile” personality of Alexander, Apollo seems a better ‘fit’ (Zeus always seems too remote). This being the case, the traditional Macedonian ‘sunburst’ symbol makes far more sense (historically) when perceived as a stylized Apollo/ sun symbol. Have I completely got the wrong end of the stick here?
Interesting idea, but it isn't right by any reckoning I've ever read. The oracle at the oasis of Siwa was an oracle of Zeus Ammon, the interpretatio graeca of the Egyptian god Amun. The Vergina sun symbol was a popular design motif all over Greece.
A Dictionary of Greek and Roman Biography and Mythology by Dr. William Smith et al (pp 144-145):
AMMON, originally an Aethiopian or Libyan divinity, whose worship subsequently spread all over Egypt, a part of the northern coast of Africa, and many parts of Greece. The real Egyptian name was Amun or Ammun; the Greeks called him Zeus Ammon, the Romans Jupiter Ammon, and the Hebrews Amon. ... [A] famous seat of the god, with a celebrated oracle, was in the oasis of Ammonium (Siwah) in the Libyan desert ... The god was represented either in the form of a ram, or as a human being with the head of a ram, but there are some representations in which he appears altogether as a human being with only the horns of a ram. ... The homage which Alexander paid to the god in the Oasis [of Siwa] is well known.
History of Greece and of the Greek People by Victor Duruy (pp 157-158):
Before entering on this expedition [into Asia] he [Alexander] thought it wise to consult a famous oracle and to cause to be decreed to himself an apotheosis which would be an additional means of dominion. He went to seek this amid the sands of Africa, in the temple of Zeus Ammon, where the priest saluted him as the son of the god. ... The Pharaohs, and after them the kings of Persia who had been masters of Egypt, had assumed the title of sons of Ammon; Alexander adopted this name as part of his spoils of war ...
Hope that helps.