Sigismund is the protagonist of the play. A Polish prince imprisoned by his superstitious father, King Vasily of Poland, since the days after his ill-fated birth, he lives alone, locked in a tower and dressed only in animal pelts for warmth. His only visitor is Clothold, his jailer and his mentor. Though Clothold attempts to educate Sigismund about the ways of the world, Sigismund’s anger at being treated so inhumanely outweighs any education that might guide him to feel otherwise. Soon after the beginning of the play, Sigismund’s father decides to bring Sigismund to the palace, to test him and determine if Sigismund is capable of ruling Poland. When Sigismund fails the test, he is imprisoned once again and asked to remember the entire confusing and chaotic episode as a dream. By the end of the play, Sigismund defies the fate that his father interpreted for him and exhibits his true and noble nature.

Rossaura is the daughter of Clothold. She is dressed as a man at the start of the play, which enables her to travel on horseback accompanied only by her servant, Bugle. She travels in search of Aistulf, the Duke of Muscovy, who has dishonored her and betrayed their love affair by courting Stella, his cousin and fellow heir to King Vasily’s throne.