He came to the throne after the ten years of confusion which followed the death of Archelaus I. But he had many enemies at home; in 393 he was driven out by the Illyrians, but in the following year, with the aid of the Thessalians, he recovered his kingdom. Medius, head of the house of the Aleuadae of Larissa, is believed to have provided aid to Amyntas in recovering his throne. The mutual relationship between the Argeadae and the Aleuadae dates to the time of Archelaus.