Alex inherited not only his father's throne, but the best equipped, trained and organized
army of that time, or indeed before or long after that time.
Legend says Alex was born on the day the
Temple of Artemis burned to the ground. He inherited the throne at 21 and had conquered the
known world (mostly
Persia) by the time of his death 12 years later. His greatest gift was to make the conquered peoples happy so that they would not
rebel later, though eventually this angered his own forces. Alex liked to found cities and name them
Alexandria, the greatest of these was in Egypt and featured the
Lighthouse of Alexandria.
For the curious I recommend
The Generalship of Alexander the Great by J.F.C. Fuller. BTW, Fuller cites
malaria as the cause of death, too.