List ways to achieve Christianization in Europe and give examples.

Ways to implement the Christianization of Europe:
– missionary preachers (Saint Patrick in Ireland, Saint Boniface among the Germanic tribes, Saint Cyril and Methodius among the Slavs);
– Conversion to Christianity of monarchs and tribal leaders (often by force);
– wars under the pretext of converting heretics to the true faith (Charlemagne converted the population of the territories he conquered to Christianity under the auspices of the Pope).