One Night in Transylvania (Hungarian: Egy éjszaka Erdélyben) is a 1941 Hungarian historical comedy film directed by Frigyes Bán and starring Zita Szeleczky, Mária Lázár and Antal Páger. It was based on the play Alterego by István Asztalos. It was screened at the Venice Film Festival.
The film One Night in Transylvania, adapted from István Asztalos's play "Alterego", unfolds in 18th-century Transylvania during the reign of Emperor Joseph II, who travels incognito through the region accompanied by his adjutant, Captain Kléber, to observe his subjects' lives firsthand. When their carriage breaks down, the emperor continues on foot in disguise, while Kléber seeks shelter at the estate of Alvinczy Krisztina, a beautiful and widowed noblewoman, to arrange repairs. Mistaking Kléber for the emperor due to his authoritative demeanor, Krisztina welcomes him warmly; charmed by her wit and independence, they share an overnight stay filled with intimate conversations blending romance and humor from the clash between his disguised imperial connections and her simple country customs.
As the night progresses, comedic misunderstandings arise from Krisztina's belief that Kléber is the emperor and her growing affection for him, viewed as a persistent but endearing suitor; their mutual bond develops through lighthearted banter and moments of vulnerability, such as discussions of loss and hardships, unaware of the true social dynamics. The next day, rumors of the emperor's visit spread among local nobility, including interactions with figures like Countess Henriette, prompting Empress Maria Theresa to summon Krisztina to Vienna upon learning of her son's provincial escapade. The empress's planned surprise exposes the full extent of the romantic mix-up, that the man Krisztina fell for was actually Kléber, not the emperor, leading to humorous chaos among courtiers and nobles, but ultimately resolving in widespread relief and approval. The central romance between Krisztina and Kléber is affirmed with Joseph II's blessing, overcoming the initial dismay and affirming their bond forged that fateful night.