Christianization (or Christianisation) is the conversion of individuals to Christianity or the conversion of entire groups at once. Various strategies and techniques were employed in Christianization campaigns from Late Antiquity and throughout the Middle Ages. Often the conversion of the ruler was followed by the compulsory baptism of his subjects. Some were evangelization by monks or priests, organic growth within an already partly Christianized society, or by campaigns against paganism such as the conversion of pagan temples into Christian churches or the condemnation of pagan gods and practices. A notable strategy for Christianization was Interpretatio Christiana – the practice of converting native pagan practices and culture, pagan religious imagery, pagan sites and the pagan calendar to Christian uses, due to the Christian efforts at proselytism (evangelism) based on the Great Commission.