The Heart of Princess Osra is part of Anthony Hope's trilogy of novels set in the fictional country of Ruritania and which spawned the genre of Ruritanian romance. This collection of linked short stories is a prequel: it was written immediately after the success of The Prisoner of Zenda and was published in 1896, but is set in the 1730s, well over a century before the events of Zenda and its sequel, Rupert of Hentzau. The stories deal with the love life of Princess Osra, younger sister of Rudolf III, the shared ancestor of Rudolf Rassendyll, the English gentleman who acts as political decoy in The Prisoner of Zenda, and Rudolph V of the House of Elphberg, the absolute monarch of that Germanic kingdom.