Probably because Greek history is mostly about Greek heroes, and
even in Parmenion's innocence, Alexander had Parmenion killed in
fearing that Parmenion might seek revenge for killing his eldest
son Philotas. (Alexander heard that Philotas was trying to kill
him)
Alexander the Great was a true Greek hero who did the
impossible, he united all the Greek states into one united country,
and took on the Persian Empire! Who ruled the world at the time! It
was a despicable act on Alexanders behalf, and considering that
Parmenion was a greek hero long before Alexander was even born, i
feel that this is most probbably one of the main reasons that
Parmenion was removed from history books. Because in stories of
heroes, they don't kill their best friends for fear of their own
lives!
