[10] Alexander came to the throne during the era of the kingdom's vassalage to Achaemenid Persia, dating back to the time of his father, Amyntas I, although Macedon retained a broad scope of autonomy.

[9] Despite his cooperation with Persia, Alexander frequently gave supplies and advice to other Greek city states, and warned them of Mardonius' plans before the Battle of Plataea in 479 BC.

For example, Alexander warned the Greeks in Tempe to leave before the arrival of Xerxes' troops, and notified them of an alternate route into Thessaly through upper Macedonia.

[13] After a court of Elean hellanodikai determined his claim to be true, he was permitted to participate in the Olympic Games[14][15][16] possibly in 504 BC, a right reserved only for Greeks.

[19][b] Alexander and his unnamed spouse[5] had at least six children:[23] Modern historians disagree on a number of details concerning the genealogy of the Argead dynasty.