Who was Alexander IV?

Recorded history tells us that in 327 BCE, Alexander married Roxane, the daughter of a warlord who ruled a small territory within the Persian Empire. What history doesn't say conclusively is whether this was a marriage of love or a political union, or a more complex situation with elements of both.
As he lay dying in Babylon, the historical Alexander was asked who would be his successor. His generals strained to hear as he uttered his last words.
What those last words were is still a topic of debate among scholars, but it is generally thought that he said: "To the greatest." To those listening, this meant that Alexander's empire must go to the mightiest of them, and the long struggle for fragments of what Alexander had built began shortly after.
Alexander's marriage to the volatile Roxane resulted in a son, who was born after Alexander died. This child was called Alexander IV (Alexander was Alexander III before he was called "the Great"). When Alexander IV was presented as Alexander's heir at the age of 13 (Roxane had wisely hidden him away until then to keep him safe), he was quickly murdered by rivals to the throne. The conquests that Alexander had held together until the end of his short life disintegrated in the power struggles that followed, and his own lineage died out with his murdered son.
Alexander IV in The Golden Vine

In the story, we first meet Alexander IV as a young man in his late 20s. He has been effectively exiled, presumably for reasons of his own safety, to his ancestral homeland of Macedon. There, he is to be trained, watched over by Alexander's mother Olympias, and to await word about when (or if) he will be named Alexander's successor.
Gradually, we find out more about the prince's childhood--how he was sullen and withdrawn, constantly compared to Alexander, and found lacking.
Author Jai Sen made key alterations to Alexander IV's story in The Golden Vine. Most importantly, he is not the child of the unstable warlord princess Roxane, but rather a Persian noblewoman named Barsine, whom Alexander met as a boy while she and her father Artabazus were exiles in King Philip's court.

As the daughter of a diplomat and courtier, as a woman nearly as familiar with the customs of Greece as she was with those of her native Persia, and as one of the first Persians Alexander would have encountered, Barsine seemed like a better candidate for the mother of Alexander's heir. Barsine was seven years older than Alexander. Still, it’s a historical fact that they were romantically involved, though they never formalized their relationship.
