A major bhakti movement, instigated in the 16th century by the immediate followers of Caitanya, at his behest, in order to promulgate and systematize his teachings and devotional practices. It was these followers—the six Gosvāmīs—who composed the works of aesthetic theology and ritual which became the scriptural basis for the Gauḍīya tradition, and who helped to establish Vṛndāvana and Mathurā as major pilgrimage sites. Central to Gauḍīya bhakti, and following a pattern established by Caitanya himself, is an intense devotion to Kṛṣṇa. This is expressed through various repetitive ritual practices, including the collective singing of kīrtanas, temple pūjā, and a theology predicated in general on Kṛṣṇa's life with the gopīs in Vṛndāvana (as narrated in the Bhāgavata Purāṇa), and in particular on the mutual erotic love between the god and his beloved Rādhā, portrayed in texts such as Jayadeva's Gītagovinda. This love is conceptualized as an expression of the spiritual relationship which exists between Kṛṣṇa, as the supreme Lord, and his human devotee (the individual soul or jīva)—a relationship ultimately characterized as acintya-bhedābheda (‘inconceivable difference in identity’). The only way to achieve the permanent realization of this connection—which is an experience of divine love (preman) concomitant with liberation (either in this body or at death)—is through a persistent and all-encompassing, yet fundamentally desireless, devotion to Kṛṣṇa.
Both the theology and practice of Gauḍīya Vaiṣṇavism have a wide variety of registers, ranging from the repetition of Kṛṣṇa's names (nāmajapa), and temple worship, to the internalized and aestheticized devotion developed by Rūpa Gosvāmī. For many Gauḍīyas, who conceived of him as either an avatāra of Kṛṣṇa or identical with the deity, Caitanya himself remained central to their practice, and was worshipped accordingly. His influence is therefore evident in a number of more and less mainstream traditions, including the Rādhāvallabhīs and the Tantric Sahajiyās, who regarded him as the joint incarnation, in one body, of Rādhā and Kṛṣṇa. For those drawing on the Sanskritic and aestheticized tradition of the Gosvāmīs, the emphasis for the devotee was more typically on assuming and enacting one of a number of different bhāvas (‘attitudes’ or ‘emotions’) towards Kṛṣṇa, ranging from servitude and subservience to the intense erotic love experienced by Rādhā and the gopīs. In practice, it was the latter bhāva which was soteriologically significant, since it could be refined and savoured as its corresponding rasa, the salvific and divine love of (and for) Kṛṣṇa.
Various guru-lineages developed in the wake of the Gosvāmīs, many of them promoting sophisticated yogic techniques based on the internalization of Braj's sacred topography and inner participation in Kṛṣṇa's līlā. For a period in the 17th and 18th centuries more physical practices, involving ritualized sexual intercourse, also seem to have been employed. Nineteenth-century urban reformers of the tradition, such as Kedarnath Datta, succeeded in establishing a more conservative theological and ritual agenda for mainstream Gauḍīya Vaiṣṇavism. This was the form in which the tradition was carried to the West by Bhaktivedānta Swāmi, founder of the International Society for Krishna Consciousness.