Constantinople, 1883. During an outing to the Black Island Edith, the adopted daughter of the French ambassador, is saved by Kalin the Eagle. She learns that he is a Bulgarian revolutionary from the April Uprising of 1876. With her help Kalin the Eagle escapes and returns to the liberated Bulgaria, where he is drawn to the socialist movement. Edith finds out that Kalin is in fact her father, and sets out in search of him. Kalin the Eagle is notable as the first movie made by the nationalized film industry after World War II in the newly formed People's Republic of Bulgaria.
The film is dedicated to the uprising, which broke out in Bulgaria in September 1923. All characters, with the exception of the leaders of the uprising Georgi Dimitrov and Vasil Kolarov, are symbolic characters. The central figures, Stefan and Peter, impersonate the motive forces behind the uprising - the workers and the peasants. They are involved in worker's strikes, in the stormy events of the First World War and the Soldier's uprising in 1918. They also participate in the bloody clashes of the September uprising and suffer its defeat after they have seen too late the need for concerted action by communists and agrarians.
The cheerful and optimistic character of Sly Peter emerged in Bulgarian folklore during the distant times of Ottoman bondage and served as an outlet protest at national and social injustices. Although the origin of Nastradin Hodzha can be traced back to the folklore of the Middle East, he, too, is a product of Bulgarian folk art. In this constant companion, noble opponent and true friend of Sly Peter are synthesized the features of the common Turkish people. The film is based on numerous stories, incidents and anecdotes in which Sly Peter and Nastradin Hodzha poke fun at the Turkish feudal authorities, the wealthy Bulgarians and Greek clergy. More than eighty proverbs have been incorporated in the dialogue.
