Kansa had a charming and virtuous sister called Devaki and she was married to Vasudev, a nobleman of the kingdom. On the wedding day, while Kansa himself was driving the bridal car according to custom, a celestial voice (‘akashvani’) announced the destruction of Kansa by a son of Devaki. The alarmed Kansa wanted to kill Devaki on the spot, but Vasudev interceded on her behalf and promised Kansa on oath that he would hand over to Kansa any child born of Devaki. This pacified Kansa, but as a precautionary measure he imprisoned Vasudev and Devaki and put trusted men to guard the dungeon. Six children of Devaki were killed by Kansa, but when Devaki conceived for the seventh time, the gods wishing to save the embryo transferred it to the womb of Rohini, another wife of Vasudev, and a report of miscarriage was sent to Kansa. This child of Rohini became famous in Hindu legend as Balram.
Devaki conceived for the eighth time and went to full term. On the eve of the midnight of Krishna’s birth, Vasudev was forewarned by the gods and instructed to take the child immediately on birth to the house of Nanda, a herdsman, on the other side of the river Yamuna. In order to avoid suspicion, he was asked to bring the child of Yashoda, the herdsman’s wife, who was to deliver a baby girl exactly at the time of Krishna’s birth, and palm off the baby as Devaki’s child.
When Krishna was born at midnight, the gods put all the guards of the dungeon to sleep and a miracle enabled Vasudev to ford the Yamuna. He transferred the babies as directed by the gods, and in the morning, gave the baby girl to Kansa. The cruel demon caught the baby by the legs and as he raised the child to dash her against the block, the babe flew off to the celestial regions as she was a goddess, and warned Kansa that Krishna, destined to kill him, was already born and was alive and well.
Krishna and Balram grew up among the herdsmen of Gokul. They survived many attempts by Kansa to identify and destroy them, and eventually Krishna killed Kansa and released his parents from bondage.
Though celebration of Krishna Janmashtami takes place in almost all parts of India but its fervor and zeal in Mathura is altogether different and majestic. Visitors from all across globe gather in large number in Mathura to observe the preparation & celebration. Janmashtami is celebrated at all places where Krishna-worship is popular, and particularly in and around Mathura, the scene of his childhood activities. Lord Krishna is essentially the god of song and dance, and the main celebrations are Rasalila dances in imitation of the youthful Krishna's moon- light dances with the Gopis (cow-girls) in the arcadian fields of Vrindavan. In certain places the celebrations include the breaking of curd-pots, hung high up in the streets, by young men forming human pyramids, in imitation of child Krishna, who was particularly fond of milk products, and used to steal, with the help of companions, butter and curds hung high in earthen pots in the kitchen to be out of reach of children’s hands.