This story is of Dwaparuga when the Sudarshan Chakra of Lord Shri Krishna burned Kashi and burned it. Later it became famous as Varanasi.
This story is as follows:
King Jarasand of Magadha was very powerful and cruel. He had countless soldiers and divine weapons. This was the reason that all the nearby kings kept their sense of friendship. Jarasand had two daughters named Asti and Prasti. They were married to King Kans of Mathura.
The arc was a very sinful and wicked king. Lord Sri Krishna slaughtered him to save the people from his atrocities. After hearing the news of the death of son-in-law, Jarasand was angry. Jarasandha, burning in the flame of retribution, attacked Mathura many times. But every time Shrikrishna used to leave him alive by defeating him. Once he collaborated with KalingaRaj Pundraq and Kashiraj, attacked Mathura. But Lord Krishna defeated them too. Jarasandh escaped but Pandurak and Kashiraj were killed in the hands of God.
After Kashiraj, his son became Kashiraj and decided to take revenge from Sri Krishna. He knew the power of Krishna. Therefore, he pleaded Lord Shiva with hard penance and asked for the groom to end them. Lord Shiva asked him to ask for any other groom. But he stuck on his demand. Then Shiva created an awful action from the mantras and said, "Vats! It will burn the state located in the same direction as you will order it to go. But keep in mind, do not use it on a Brahmin devotee. Otherwise its effect will be futile. "By saying this, Lord Shiva was interrupted.
Here, after killing the wicked Kalayavan, Shri Krishna came to Dwarka with all the Mathuravas. Kashiraj sent the act to Dwarka to kill Krishna. Kashiraj did not have the knowledge that Lord Shri Krishna is a Brahmin devotee.
Therefore, even after reaching Dwarka, the act could not harm them. Inverted Shrikrishna turned his Sudarshan Chakra towards him. Sudarshan fiercely swept towards action. The act of looking into the life of the soul is frightened and turned towards Kashi. Sudarshan Chakra also started following him. Coming to Kashi, Sudarshan consumed the operation. But still his anger did not calm down and he consumed Kashi.
In the earliest times, this city will be restored between two rivers Vara and Asi. Due to the settling between the wind and the rivers of Asi, this city was named Varanasi. Thus Kashi was reborn as Varanasi.