context: The first crusade to Finland is a crusade from Sweden to southwestern Finland in the 1150s. [1] There is no certainty about the reality of the crusade. However, some extensive military journey was made from Sweden to Finland in the 1150s. [2] However, a military trip cannot be considered a true crusade, but a typical military trip, a so-called ledung trip. [3] The purpose of the mythical expedition was to prevent the invasion of Sweden by the Finns and to spread the Catholic faith to pagan southwestern Finland. [4]
question: Why did the first crusade take place?
answers.text: was to prevent the invasion of Sweden by the Finns and to spread the Catholic faith to pagan southwestern Finland