Lord Shri Krishna was born at 12 o’clock on the eighth day of Krishna Paksha of Bhadra month. Krishna is the 8th incarnation of Vishnu who was born in the Dwapara Yuga to protect people from the atrocities committed by their maternal uncle Kansa.
Since Lord Vishnu incarnated directly on this earth and it was his physical incarnation, that day is celebrated as Krishnashtami or Janmashtami.
According to the beliefs of Dwapar era, there used to be a king named Kansa in the kingdom of Mathura. Who, in the greed of power, had even locked his father in prison and started torturing him.
Gradually, his torture increased to such an extent that on the day of his own sister Devaki’s wedding, there was a voice in the air that Devaki’s mortal child would kill him.
Hearing this, the cruel ruler Kansa, who believed himself to be God, was furious and took up arms to kill his dear sister Devaki and brother-in-law Vasudev.
Stopping him, Devaki promised that Kansa could kill him as soon as his child was born.
While doing so, Kansa killed 6 children of Devaki. Then all the gods planned together and without knowing Kansa placed the seventh child of Devaki in the uterus of Rohini, the second wife of Nanda.
This seventh child was born as Balarama. According to All India Radio, at the time of the birth of the eighth child, all the guards fell asleep one by one and all the doors of the prison were also opened.
Nand raised Shri Krishna on his head and proceeded towards the house of Nand Maharaj living in Gokul. He replaced Nanda’s home-born daughter with Shri Krishna.
When Kansa reached to kill the goddess, Yoga Maya, born as a child, made her aware of the truth that her era was born. Hearing this, Kansa ordered all the children born in Mathura to be killed.
He also took help of various elusive demons but could not succeed. After growing up, Krishna killed Kansa in the Malla war and freed the Mathura people from his atrocities.