Kunti was the first wife of Pandu. She was daughter of the king of Matura. In young age she got the blessing of a saint that she could invite any celestial god and beget a son from him. When Pandu decided to go in jungle she with the second wife Maadri also followed him. During his jungle visit Dhritarashtra took care of his throne on his behalf.
In jungle Kunti came to know about the curse given to him. She told Pandu about the Mantra which Durvasa Muni given her. Pandu agreed to have child through this process. After getting permission from his husband Kunti first summon to Yam, Dharmaraj, The god of Justice. "My child will be the ultimate of truth and justice on earth" he named him Yudhishthir (who remain strong and do not leave the path of truth even during the war).
Pandu asked her again to have second son Kunti pray to Pavan Devta, the air god " My son will be the strongest person on the earth no body will be able to beat him face to face war" he named him Bheem.
Pandu still not satisfied he asked once again to call Indra, King of all Devta, "My son will be the excellent worrier and his fame will above all, He will be the closest person of the Lord Krishna, incarnation of Vishnu on earth". He named him Arjun.Maadri was sad, as she was not having any child also. Pandu asked Kunti to give that Mantra to Maadri also so that she also can have children. Maadri summon to Ashwani Kumar (twin gods, God of medicine and surgery) and god two sons from them. Both were strong and handsome they named them Nakul and Sahdev.