There are four Sampradayas from the beginning of the creation. One is called Brahma Sampradaya, and is coming down by disciplic succession from Brahma; another Sampradaya is coming down from Laksmi, called Sri Sampradaya; another is coming down from the Kumaras, they are known as Nimbarka Sampradaya; another Sampradaya is coming from Lord Siva, Rudra Sampradaya or Visnu Svami. These are four bona fide Sampradayas that are accepted by the bona fide spiritualists. The Impersonalist Sampradaya is not original neither the Impersonalist Sampradaya or party can help us.
Anyway, all the four Sampradayas above mentioned, they are after worshiping the Supreme Lord Visnu, in His different Expansions, and some of them are in favor of worshiping Radha Krishna. In the later age the Brahma Sampradaya was handed down though Madhva Acarya; in this Madhva Acarya disciplic succession came Isvara Puri. This Isvara Puri was accepted as Spiritual Master of Lord Caitanya. Therefore, we being in disciplic succession of Caitanya Mahaprabhu, we are known as the Madhva Sampradaya. And because Lord Caitanya appeared in Bengal, which country is called Gaudadesa, our Sampradaya party is known as Madhva Gaudiya Sampradaya. But all these Sampradayas are non-different from one another because they believe and worship the Supreme Lord.
Bhaktivedanta Swami in a letter to Upendra; Los Angeles, 13. February 1968