Once Koshala was a great kingdom, & king Sagara was performing Ashwamedha Yagna suddenly he lost the track of sacrificial horse. He sent his 60 thousands sons to find the horse. They searched horse in every corner of earth & destroyed everything that came in their path. At last they reached to sage Kapila asharam & the saw the horse tied their. They shouted on sage of stealing the horse that made Kapila enraged & he burned all of them in ashes. King Sagara waiting for his sons send his grandson Anshuman to whom Kapila said that only performing Dah Sanskara of all of them on the presence of sacred river Ganga would yield them Nirvana. Many kings of dynasty performed austere penance but could not bring Ganga on earth by the time their curse multiplied & it started to destroy the Koshala kingdom. And then king Bhagirathi did penance for 1000 years & made Lord Brahma happy to send Ganga on earth, but the force of river was so destructive that earth will not be able to hold it. For that Brahma told Bhagirathi to pray Lord Shiva. After a year of penance Lord Shiva appeared & told Bhagirathi that his wish would be fulfilled. When Ganga was falling from heaven everybody was so afraid that everything would be destroyed. Ganga became proud of his power & came forcefully. As it was going to hit the earth Lord Shiva captured it in his Jata. Ganga was helpless to come out of it. At this Bhagirathi prayed Shiva again & said the cause is something else at this Lord Shiva released Ganga crushing her vanity. Ganga flowed behind Bhagirathi giving liberation to all his ancestors & reached near Varanasi. Varanasi is eternal abode of Shiva so to pay the homage to the city Ganga flew Northward. Whoever dies in this city of Shiva Ganga takes them straight to the heaven.