Given the question: Who does the commander of the Sacred guard fall in love with?  Answer the above question based on the context below:  The story is set in 490 BC, the time of the Medic Wars, during which Persian armies sweep through the Ancient world. Having brought home to Athens the Olympic victor's laurel crown, Phillippides becomes commander of the Sacred Guard, which is expected to defend the city-state's liberty, a year after the expulsion of the tyrant Hippias. Athenian supporters of Hippias conspire, hoping to sideline Phillippides with a marriage to Theocrites' expensive servant Charis, and thus neutralize the guard. She fails to seduce him, as his heart is already taken by a young girl before he learns her name is Andromeda, daughter of Creuso. Everything personal is likely to be put on hold when the news breaks that the vast army of Darius, the Persian King of Kings, is marching on Greece, hoping that its internal division will make its conquest a walk-over. Theocrites instructs Miltiades to hold back the Sacred Guard to defend the temple of Pallas after a likely defeat, and proposes instead to negotiate terms with Darius, but is told an alliance with Sparta could save the Hellenic nation. Phillippides makes the journey and survives an attempt on his life by conspirators; he returns with Sparta's engagement during the Persian attack in far greater numbers on Militiades valiant troops. Charis, left for dead after overhearing Darius's orders, reaches the camp to tell that the Persian fleet, now commanded by the traitor Theocrites, is heading for the Piraeus to take Athens. Miltiades sends Phillippides ahead to hold out with the Sacred Guard until his hopefully victorious troops arrive, and after his perilous journey back they successfully beat back the Persians.
The answer is:
Andromeda