Thaddeus Sobieski (tah-DAY-uhsh soh-BEE-skih), actually the illegitimate son of an English aristocrat named Sackville. Reared in Poland by his mother and grandfather, he becomes a Polish patriot, fighting against Russia as long as he can. He finally becomes a refugee in England, taking the name of Mr. Constantine. He is put into debtors’ prison because he cannot pay his bills from his small income as a tutor. He is rescued by his friend Pembroke Somerset, who turns out to be his half brother. Somerset recognizes the relationship and gives Thaddeus a portion of the family fortune so that Thaddeus can marry and settle down to a comfortable life as an English gentleman.
Count Sobieski, Thaddeus’ grandfather and an enlightened Polish noble. A great Polish patriot and soldier, he is killed while fighting against the Russian oppressors of his country. Proud of his name, he makes Thaddeus promise to use no other.
Pembroke Somerset, a young English adventurer who fights for the Russian czar. He is captured by Thaddeus and becomes his friend. Later, he befriends Thaddeus in England and turns out to be Thaddeus’ half brother.
General Kosciusko (kosh-TYEWSH-koh), the famous Polish patriot. He is one of Thaddeus’ commanding officers.
General Butzou (BEW-tzuh), a Polish patriot and the friend of Thaddeus’ family. Thaddeus befriends him when the two are refugees in London.
Mrs. Robson, Thaddeus’ kind landlady in London.
Dr. Vincent, a money-hungry doctor who overcharges Thaddeus in London.
Lady Tinemouth, an Englishwoman rescued by Thaddeus from ruffians in Hyde Park.
Mary Beaufort, a young English woman who befriends Thaddeus, falls in love with him, and marries him. She is Pembroke Somerset’s cousin.
Lady Sara Ross
Lady Sara Ross, Lady Tinemouth’s friend. She tries to involve Thaddeus in an affair.
Dr. Cavendish, a London doctor who is kind to the Polish refugees.
Lady Dundas, an English woman who hires Thaddeus as a tutor for her daughter.
Euphemia Dundas, one of Thaddeus’ pupils. She becomes infatuated with him.
Diana Dundas, another of Thaddeus’ pupils.