Happy Shiv Rathri
The Pradhana Vaishnava is Lord shiva,. It is quoted in Srimadh Bhagwatham.
SB 12.13.16 — Just as the Gaṅgā is the greatest of all rivers, Lord Acyuta the supreme among deities and Lord Śambhu [Śiva] the greatest of Vaiṣhṇavas, so Śrīmad-Bhāgavatam is the greatest of all Purāṇas.
Five thousand years ago when Krishna wanted to engage in His Maha Rasalila, Lord Shiva and his wife, Parvati Devi, very much wanted to see this event. Mother Parvati was allowed to enter the arena of the Rasalila, but as Lord Shiva tried to enter, he was told that he could not come due to the fact that he was possessed of a male body.
It was explained by the gopi Vrinda (after whom Vrindavan is named) that no male except for Krsna was allowed to enter into this Rasa arena.
Lord Shiva feeling so much distressed being denied access into the arena, began to cry very intensely. Seeing His heart’s remorse, Vrindadevi felt great compassion and decided she would enable Lord Shiva to enter into the arena of the Rasa Lila. Vrindadevi told Mahadev to go to Manasarovar to take bath and explained that if he did so, he would be able to enter into the Rasa arena.
Following the instruction of Vrindadevi, Lord Shiva after coming out from the water had attained a female form. He then went to the arena of the Rasalila where Krsna upon seeing this new gopi, called “her” Gopishvara. At this, Srimati Radharani became upset. “Why is it you are calling this particular gopi by this name. I am Gopishvara.” Krishna then explained the situation and Srimati Radharani became most happy.