A.C. Bhaktivedanta Swami (1896-1977), known as Prabhupada among his disciples, founded ISKCON on July 13, 1966. Bhaktivedanta is the founder of the International Society for Krishna Consciousness, and ISKCON members recognize him as a spiritual master in the sampradaya, or lineage of teachers, that stretches back to the founder of Gaudiya Vaishnavism, Chaitanya (1486-1533).
A Hindu reformer active in 16th-century Bengal, Chaitanya taught a system of exclusive devotion to the Hindu God Krishna, whom members of his lineage recognize as the "Supreme Personality of Godhead." The hagiographic literature declares that his own disciples began to recognize Chaitanya as an avatar, or appearance of the divine, even during Chaitanya's lifetime, and today ISKCON members look back on the founder of their lineage as not only a religious teacher, but as an incarnation of Krishna himself. Chaitanya introduced both the main theological concept of Gaudiya Vaishnavism, namely the centrality of Krishna, as well as its core practice, that of devotionalism, or bhakti, as expressed through public congregational chanting. Chaitanya also taught the need to publicly preach about Krishna and to seek devotees, providing the proselytizing impetus that later led to ISKCON.
If Chaitanya represents the foundation of ISKCON's parent lineage, Bhaktivedanta's own guru, Bhaktisiddhanta Saraswati (1874-1937), represents the bridge between the received tradition and the modern Hare Krishna movement. Born within a Gaudiya Vaishnava family, Bhaktisiddhanta sought to return the Chaitanya tradition to its roots, and also modernize it for a new century. Many of Bhaktisiddhanta's teachings considered social issues such as the reform of social support institutions, but he primarily focused on the Hindu caste structure.
Chaitanya had implicitly rejected caste divisions among his own disciples, permitting Brahmins (priestly caste members) and non-Brahmins to become followers, and explicitly taught a single bhakti (devotional) path of worship accessible to all people, regardless of caste or station. However, in the nearly four centuries since the tradition's founding, caste had become stratified within the Gaudiya lineage, with firm divisions between Brahmins, lower caste devotees, and the large number of untouchable (caste-less) Krishna devotees in Bengal.
Bhaktisiddhanta worked to overcome these barriers through both words and action. In addition to speaking and publishing against caste divisions, Bhaktisiddhanta ignored the caste identity of those who sought initiation from him into the Gaudiya Vaishnava lineage, granting all such individuals the mantras and sacred thread normally reserved for Brahmins. In doing so, Bhaktisiddhanta laid the groundwork for the spread of the tradition to the West. Since traditional Hinduism considers Westerners completely outside the caste system and therefore excluded from such religious rites as initiation, A.C. Bhaktivedanta would not have been able to initiate his American and European -- and later African and East Asian -- disciples without his guru Bhaktisiddhanta's example.
In 1922, Abhay Charan De, the future A.C. Bhaktivedanta Swami Prabhupada, met Bhaktisiddhanta Sarasvati. Raised in a Gaudiya Vaishnava family, Abhay had shown an interest in religion from a young age. Though trained in traditional Gaudiya spirituality by the family guru, the future founder of ISKCON had also benefited from the best of British colonial education, graduating from the Scottish Church College of Calcutta with a degree in chemistry. A successful pharmacist, husband, and father, Abhay Charan De was also interested in religious matters, and when he encountered Bhaktisiddhanta, he became more involved in the Gaudiya Vaishnavism in which he had been raised.
On November 21, 1932, Abhay Charan De received formal initiation from Bhaktisiddhanta into the Gaudiya Vaishnava lineage, an act that entitled him to learn the sacred mantras, but also required daily devotional practices. At the urging of his guru, he undertook efforts to spread Gaudiya Vaishnavism among an English-speaking audience, publishing articles and leaflets, and beginning work to translate the central texts of Vaishnavism into English. In recognition of his work, the other members of his lineage granted Abhay Charan De the honorific title Bhaktivedanta in 1939. Over the next twenty years, Bhaktivedanta would self-publish a newsletter, called Back to Godhead, found a short-lived religious association called the League of Devotees, and begin a full translation of one of the religion's central texts, the Bhagavata Purana (also called the Bhagavatam), into English, all the while continuing to work as a pharmacist and supporting his family.