Parshuram was Lord shivas disciple and he even fought with Lord Shiva once .During this fight lasting 21 days Parshuram hit Shiva with his Parashu .It struck Shiva on his head and created a wound on his forehead . Lord Shiva was mighty pleased with his disciple and hence preserved the wound as it is .
Shri Parshuram cut the thousand arms of sahastrarjun with his parashu and killed him .Lord Indra who possessed Shiva Vijay dhanush handed this bow to Shri Parshuram .With the help of this bow Lord Parshuram wiped out Kshatriyas from the earth 21 times .
Later on Sri Parshuram handed over this bow to Karna for his intense devotion to him .Karna used this very bow to fight on the 17th day of the Mahabharat war .
