Bhageerath was the son of Dileep (Sagar > Asamanjas > Anshumaan > Dileep > Bhageeerath). he di severe penance to please Gangaa. Gangaa did get pleased with his tap and appeared before him and asked him to ask for any boon. Bhageerath told her his objective. Gangaa said - "Surely I will come down on  Earth but, the problem is that when I will fall on Prithvi, I will fall with a great force. If I will fall just like that the Prithvi will got to Rasaatal, so better you please Shankar Jee so that he can bear me. It is only he who can bear me." and she disappeared.

Bhageerath then did Tapasyaa for Shiv jee and pleased him. SHiv Jee appeared before him and asked him to ask for a boon. Bhageerath told him the whole story and prayed him to bear Gangaa when she falls from Heavens. Shiv got ready to do that and asked him to invoke Gangaa. Bhageerath invoked Gangaa, Gangaa fell on Shiv's head, but lost her way in the matted locks of Shiv Jee. Bhgeerath again prayed Shiv jee, so Shiv Jee opened a few strands of his locks and then only Gangaa found her way. As she descended, she asked Bhgeerath to guide her to where he wanted to take her. So Bhageerath sat in his chariot and proceeded towards the spot where his ancestors were burnt into ashes.

In the way, there was an Aashram of Muni Jahnu who was doing worship there, when Gangaa passed from there, she flowed his worship material. Muni Jahnu got angry and drank all waters of Gangaa. Bhageerath was going forward, but when he looked back he did not see Gangaa coming after him. He got worried and came to know that Muni Jahnu had drank all her waters. He prayed him to release Gangaa for his ancestors. So Muni released from his ears. And Gangaa again followed Bhageerath. From this Muni Jahnu considered Gangaa as his daughter so she is called Jaahnavee.

Then Bhageerath took her to the place where his ancestors' ashes were lying. As Gangaa water touched those ashes, his all ancestors got Mukti.

His mission was successful. Since Bhageerath brought her on Prithvi, she is called Bhaageerathee too.