Alexander, the king of Macedon, eager for conquest and glory, but generous and merciful when victorious. Passionately enamored of his captive, Campaspe, he asks Apelles, his court painter, to paint her portrait. He becomes suspicious of Apelles and angrily jealous, but finally he is moved to allow the lovers to marry because, as he says, a man who cannot command himself is unworthy to command the world.
Hephestion (hee-FEHS-tee-uhn), Alexander’s chief general. Worried about the softening influence of love on the great warrior, he rejoices when Alexander conquers his desire for Campaspe and returns to military conquest.
Diogenes (di-OJ-eh-neez), a crusty independent philosopher. Scorning luxury and emotion, he lives in a tub. Even Alexander’s glories do not impress him. Alexander is forced to admit that if he were not Alexander he would like to be Diogenes, who has neither wants nor fears.
Apelles (uh-PEHL-eez), Alexander’s painter. He loves Campaspe, he thinks hopelessly, for he knows that Alexander loves her also. He wins her love while painting her portrait and finally receives her at Alexander’s hands.
Campaspe (kam-PAS-pee), Alexander’s beautiful and virtuous Theban captive. At first skeptical of Apelles’ love, she later accepts and returns it.
Sylvius (SIHL-vee-uhs), an Athenian citizen who wishes the unwilling Diogenes to instruct his sons.
Manes (MAY-neez), the discontented servant of Diogenes.