The word 'Poika' means 'Boy' in Finnish. However, the character 'Poika' is played by a girl 'Sonja Petäjäjärvi'.
The later scenes in the movie were shot first. For example Sonja Petäjäjärvi's character 'Poika' had her blood make-up already during her first takes, so the meeting scenes in the village (her first appearance in the movie) were shot later on.
The background of the film is set in the historical Russo-Swedish War (1590-1595). The war was fought over possession of the Duchy of Estonia. At the end of the war, Sweden ceded some territories to Russia, but managed to remain in control over Estonia. Russia had to renounce all claims on Estonia.
The film is set in the borders of Finland, which was then under Swedish rule. Swedish rule in Finland was established in the 13th century, through a number of Northern Crusades. It lasted until 1809, when Sweden lost the so-called Finnish War (1808-1809). It was forced to cede Finland to the victorious Russian Empire.