Multiple choice Why did Phillip II not conquer Persia ? The empire was too big He never wanted to He was killed first He wanted his son to do it Reveal answer Fill a bubble to check yourself C Correct answer Explanation King Philip II of Macedon was planning an invasion of Persia and had already sent an advance force, but he was assassinated in 336 BC before he could lead the main campaign himself. His son Alexander then took up the task.