The Christianization of the Kingdom of Iberia refers to the spread of Christianity in the early 4th century as a result of the preaching of Saint Nino in the ancient Georgian kingdom of Kartli, known as Iberia in classical antiquity. The then-pagan king of Iberia Mirian III declared Christianity to be the kingdom's state religion. According to Roman historian Sozomen, this led the king's "large and warlike barbarian nation to confess Christ and renounce the religion of their fathers", as the polytheistic Georgians had long-established anthropomorphic idols, known as the "Gods of Kartli". The king would become the main sponsor, architect, initiator and an organizing power of all building processes.