Sage Gautama had a son named Saradwat, who was born with arrows in hand. Saradwat had a keen aptitude for learning about the weapons. He acquired many weapons by means of the austerities through which students would acquire the knowledge of the Vedas.
Indra, the God of the celestials became afraid of Saradwat and sent a celestial damsel named Janapadi to entice Saradwat and distract him so that he would lose his concentration on learning. Seeing Janapadi appear before him clad only in a single piece of cloth, Saradwat was momentarily stunned. His bows and arrows slipped from his hands. Though his ascetic way of life enabled him to overcome the temptation, the feelings stirred up in him for a moment resulted in his semen falling on to a bush of weeds. He left the place quickly to avoid the damsel.
The semen that fell on the bush of weeds divided the bush into two parts and two children, twins, sprang from the two parts. The presence of the twins was noticed by a soldier accompanying King Santanu, who was in the forest on a hunting exercise. Seeing the deer skin and the bow and arrows abandoned near that place by Saradwat, the soldier thought that the twins should be the children of a sage. He took the children along with the deer skin, the bow and the arrows to King Santanu. Santanu took the children to his palace, performed the religious ceremonies prescribed and named them Kripa and Kripi.
Saradwat left his former abode but continued his study of the Science of the Weapons by settling down at another place. Because of his insight developed through his spiritual pursuits, he became aware that his son and daughter were being brought up by Santanu. He went to Santanu, identified himself as the father of Kripa and Kripi and narrated to him what had happened. With Santanu's consent, he taught Kripa the four branches of the Science of arms, and various other recondite subjects. As a result, within a short time, Kripa became an expert in the Science of Arms.
Dritarashtra wanted the Kauravas and the Pandavas to become well versed in the Science of Arms and other branches of knowledge. With Kripa's eminence having become widely known, he sent the princes to Kripa, after consulting with Bhishma. The Kauravas and Pandavas were well groomed by Kripa under whom many other princes also got trained.