Ganga was a goddess belonging to heaven and she was brought to earth through Shiva’s locks of hair. She was brought to earth to provide purification to the entire human beings.
Once, there lived a king named Sagara who had sixty thousand sons. He once conducted Ashwamedha Yagya to declare his supremacy. The king set his horse free to roam around the earth accompanied by his sons. The places the horse went would be pronounced as king’s property. Lord Indra, the ruler of heaven, wanted to stop the horse to mitigate king Sagar’s supremacy. He stole the horse and tied it to Sage Kapil’s hermitage.
When Sagar’s sons found the horse in the hermitage, they mistook sage as the stealer of the horse, and started attacking him. The sage was in deep meditation for years, and got disturbed by all the chaos. He opened his eyes in anger and all the men were burnt to ashes. The souls of these 60,000 men wandered as ghosts, since their final rites had not been performed. Only Ganga could cleanse the souls and redeem them.
Penitence By Bhagiratha
One of the descendants of Sagara named Bhagiratha did severe penitence to Brahma to bring down Ganga to Earth. Pleased with the prayer, Brahma agreed to grant his wish. He ordered Ganga to flow to earth to give moksha to King Sagar’s sons. Ganga was arrogant and refused to do so. She, in her anger, wished to sweep through the earth and destroy everything. Bhagiratha got terrified by this intention and prayed to Shiva. Ganga arrogantly fell from heaven on Shiva’s locks. Shiva broke up Ganga’s descend and made the powerful water body into different streams. It is believed that Ganga reached earth in the form of seven rivers after meandering through Shiva’s thick matted locks. The holy water of Ganga touched the ashes of Sagar’s sons and replenished their souls.
The seven streams of Ganga are Bhagirathi, Janhvi, Bhilangana, Mandakini, Rishiganga, Saraswati and Alaknanda.