Sri Krishna Janmashtami is the birthday of Lord Krishna, the eighth incarnation of Lord Vishnu. Lord Krishna incarnates on the day when Rohini Nakshatra and Ashtami meet in Singha month. It is believed that Lord Vishnu incarnated as Krishna to restore dharma when the goodness of the world had deteriorated.
Tired of the actions of the Asuras, Goddess Bhumi came to the Devaloka in the form of a cow and explained the matter. The gods accompanied Bhumi Devi and reached Brahmaloka and saw Brahma and convinced them of their problem
But Brahma said that he could not kill Kamsa because he had given him a boon. Then they all went to Palazhi and met Vishnu. Vishnu heard their grievances and announced that he would incarnate on earth and vanquish the demons for the benefit of the world and reduce the overburden of the earth. Thus, Janmashtami is the day when Lord Vishnu was born on earth after receiving Shri Krishna Avataram.
source of data
https://malayalam.samayam.com/spirituality/know-all-about-krishna-janmashtami-festival-history-in-malayalam/articleshow/70686727.cms
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