(in English): The thesis deals with the history of arianism. It emphasizes the historical and theology-philosohical conext of arianism, which is essential for understanding the whole topic and especially for understanding the development of the early Christians' faith. It outlines how the early Christians perceived their faith, which is important in order to grasp the basic principles and understanding of early beliefs also outlines the context of late antique philosophy that influenced the theological-philosophical framework of orthodoxy and arianism itself. The text of the thesis focuses on the political situation in Europe at the end of antiquity, the rise of arianism in the first half of the fourth century and its dispute with orthodoxy, whose dogma has been defined during the council of Constantinople (381). Already before the beginning of second council in Constantinople arianism started to spread through the barbarian tribes, the Goths, Vandals and Burgundians to the West, where it was incorporated into the policy of tribal States. Thanks to these tribes arianism survived in the West until the sixth century. The thesis brings incentive for further research of Arianism in the context of religious and political relations in the Western and Eastern parts of the Roman Empire in the early Middle Ages.