Alexander with a horned diadem. Coin by Lysimachus.
Alexander The Great was associated with Hercules, son of Zeus and may have believed himself the son of the Egyptian god Ammon, as well as the mortal king Philip. Stories about Alexander’s birth were embellished in order to fit someone of such an illustrious pedigree. Peter Green, in the second chapter of Alexander of Macedon 356-323 B.C., names some of the prodigious events that attended the conception and birth. These are also described by Plutarch.
1. The temple of Artemis burned, according to tradition, on the night on which Alexander The Great was born. The Persian Magi foretold great disaster fot the Persian Empire.
Plutarch on the birth of Alexander: “Alexander was born the sixth of Hecatombaeon, which month the Macedonians call Lous, the same day that the temple of Diana at Ephesus was burnt..the temple..took fire and was burnt while its mistress was absent, assisting at the birth of Alexander. And all the Eastern soothsayers who happened to be then at Ephesus, looking upon the ruin of this temple to be the forerunner of some other calamity, ran about the town, beating their faces, and crying, that this day had brought forth something that would prove fatal and destructive to all Asia” -Plutarch’s Life of Alexander-
2. His mother Olympias dreamed on the night before her wedding, that she was penetrated by a thunderbolt. Fire spread out in all directions. Plutarch writes: “The night before the consummation of their marriage, she dreamed that a thunderbolt fell upon her body, which kindled a great fire, whose divided flames dispersed themselves all about, and then were extinguished”.
3. Alexander’s father Philip looked inside his wife bedroom and saw her in the embrace of a snake. This was interpreted to be the god Zeus-Ammon, who was considered by some to have been Alexander’s father.
4. Another birth omen of a sort is reported by Plutarch who writes that Alexander’s father Philip received news of the birth of his son in a message containing three pieces of good news. The two others were that his race horse had won in Olympics and that Parmenio had beaten the Illyrians.
Source : N.S. Gill
http://ancienthistory.about.com
World Of Alexander The Great 
Such great signs proved right to history.
It is quite possible that he was associated with Hercules – who can disprove it!!!
Alles gut. Danke.
Liebe Grüsse von uns Gisela und Wolfgang
Such a different world. On a personal level I don’t believe any of these omens. But I think people back then did believe. Although I would like to read what Aristotle thought of all this.