Dvapara Yuga mein Mathura ka raja Kansa ek atyachari shasak tha. Jab uski behen Devaki ka vivah Vasudev se hua, toh ek akashvani hui ki Devaki ki aathvi santan Kansa ka vadh karegi. Kansa ne dar ke maare dono ko karagar (jail) mein daal diya aur unke saare bachhon ko ek-ek karke maar diya.

Bhadrapada mahine ki Krishna Paksha ki Ashtami tithi ko, adhiri raat mein Bhagwan Vishnu ne Devaki aur Vasudev ke samne apna divya roop prakat kiya aur bataya ki vo Krishna ke roop mein janam le rahe hain. Unhone Vasudev ji se kaha ki vo unhe turant Gokul mein Nand Baba aur Yashoda Mata ke ghar chhod aayein.

Usi samay karagar ke saare pehredar gahri neend mein so gaye aur saare darwaze apne aap khul gaye. Bahar bhari barish ho rahi thi aur Yamuna nadi ufan par thi. Jab Vasudev ji naye janme Kanha ko tokri mein lekar nadi par kar rahe the, toh Sheshnag ne unpar chhatra banakar unki barish se raksha ki. Yamuna nadi ne Kanha ke charan sparsh kiye aur unhe rasta diya.

Vasudev ji ne surakshit roop se Krishna ko Gokul pahunchaya aur vahan se Yashoda ji ki kanyaroopi Maya ko lekar wapas Mathura aa gaye. Subah jab Gokul mein sabko pata chala ki Nand Baba ke ghar beta hua hai, toh poore Gokul mein jashn manaya gaya. Is tarah Bhagwan ne dharti par dharm ki sthapna ke liye janam liya, aur isi din ko hum har saal badi dhumdham se Krishna Janmashtami ke roop mein manate hain.