So, this is something I've long wondered. Alexander the Great's conquest and subsequent rule of Persia was cemented when he wed one of Darius III's daughters, Darius had had no sons and therefore no male heir to succeed him or cause trouble. But what if he had? What would this son be able to do facing Alexander? Especially if he were around 15/16 at the time of the Battle of Issus? Would the boy die with his father, or be executed by Alexander?