Budheshwar Temple, Varanasi

 According to Kashi Khand, once Chandra (Moon) got deeply infatuated with Tara, wife of Brihaspati. Despite warnings by Devas, Chandra forcibly took Tara with him. In spite of many requests and pleadings Chandra kept Tara with him for several days and refused to part with her.The matter was referred to Rudra Dev who attacked Chandra with a weapon called Pinak. Chandra also retaliated. However, at the end Tara was separated from Chandra and handed over to Brihaspati.

Soon Brihaspati realised that Tara was pregnant. He asked her to get rid of that to-be born child from her womb. She did so in the garden, but by that time the child was fully developed. The moment the baby touched the ground, the entire assemblage of the Devas came to know about the birth of a child. All of them insisted on knowing from Tara as to who was the father of the child, but Tara kept silent.

In the meantime, the newly born child who was very intelligent (with Buddhi) threatened that he would curse Tara unless she revealed the truth. Finally Tara revealed that Chandra was the father of the child. Considering the high level of intelligence of the child (Buddhi), he came to be called Budha. Budha sought permission from Chandra to go to Kashi and pray to Lord Shiva, to which Chandra agreed.

Budha came to Kashi, installed a Ling and started worshipping Lord Shiva for several years. Finally Lord Shiva appeared before him and blessed him stating that the Ling installed by Budha be known as Budheshwar and those who worship this Ling will attain highest level of intelligence and such level of intelligence will always remain with the devotee despite his age. (Kashi Khand, Chapter fifteen).