Pantheia was the wife of the King Abradatas of Susa. It is unlikely that she was an actual historical character but instead was probably either a literary creation of Xenophon himself or a mythological or folkloric figure about whom Xenophon heard during his travels in Persia.
The Cyropaedia, or Education of Cyrus, was written by by Xenophon (c. 431 BC–354 BC) in approximately 370 BC. Xenophon, although an Athenian, was not an admirer of Athenian democracy. A follower of Socrates, Xenophon was disgusted by the execution of Socrates for impiety by the Athenian democracy and himself served as a mercenary for Cyrus the Younger, a contestant for the throne of Persia. He eventually became a friend of the Spartan King Agesilaus II. The story of Cyrus is intended to illustrate the virtues of a good king and is thus an implicit rebuke to democracy.
Book 6 describes how Pantheia was captured in the fighting and given into the custody of Araspas, a Median officer. Araspas, contrary to Cyrus' instructions, attempts to rape her. She appeals to Cyrus, and he protects her, showing himself as having a noble character. This fair and just treatment of Pantheia causes King Abradatas to side with Cyrus.
When Abradatas is killed in the fighting, Pantheia commits suicide. She is intended as a model of a brave and virtuous woman and also as an illustration of the virtues and justice of Cyrus.