The Bhakti movement was a Hindu religious movement of the medieval period that promoted the belief that salvation was attainable by everyone. The movement is closely related to Islamic Sufism, which appeared around the same time: both advocated that a personal expression of devotion to God is the way to become at one with him.The Bhakti movement originated in seventh-century Tamil Nadu and spread northwards through India. While the southern movement favoured devotion to Shiva, Vishnu and his avatars, the northern devotional movement was centered on Rama and Krishna, both of whom are believed to be incarnations of Vishnu. Despite this, the sects of Shiva or of Vishnu did not go into decline. In fact, for all of its history, the Bhakti movement co-existed peacefully with the other movements in Hinduism. It was initially considered unorthodox, as it rebelled against caste distinctions and disregarded Brahmanic rituals, which according to Bhakti saints were not necessary for salvation. In the course of time, however, owing to its immense popularity among the masses (and even gaining royal patronage) it became 'orthodox' and continues to be one of the most important modes of religious expression in modern India.