Once Durvasa paid a visit to the palace of Kuntibojan. The king appointed his foster daughter Kunti to serve the sage and look after his needs. Kunti sincerely performed her duties with care, patience and devotion. Pleased with her sincerity, Durvasa gave her a divine mantra. He said, "If you call upon any God repeating this mantra, he will manifest himself to you and bless you with a son equal to him in glory."

The impatient curiosity of youth made Kunti test the efficacy of the mantra by repeating it and invoking the Sun, whom she saw shining in the heavens. The Sun God approached Kunti with ardent, soul-scorching admiration. Kunti was aghast and asked him to go back and forgive the childish folly of hers.

But the mantra held him and so Kunti conceived by the grace of the Sun God and gave birth to Karna who was born with divine armour and earrings and was bright and beautiful like the Sun. To hide her fault, she placed him in a sealed box and set it afloat in a river. The child was spotted by a charioteer and was brought up in his house.(Refer to Karnas Birth)

Vyasa answered the call of his mother Satyavati and bore upon the wives of his half-brother and their maid, three sons - Dhritarashtra, Pandu and Vidura. Dhritarashtra was blind; Pandu was pale-skinned and Vidura, the son of the maid.

Bhishma thus made Pandu, the pale-skinned nephew, king of the Bharata race. When the princes were old enough, he cast around (as he had done for their father Vichitravirya) for wives for them.

When he heard that the king of Kunti was holding a swayamvara for his daughter, Bhishma sent the king Pandu to it. Kunti Devi saw him and the splendor of the Bharata race shone on his features and his countenance. She chose him over the assemblage and thus it was that Pandu brought home to Hastinapura, his new queen Kunti.

Meanwhile, Bhishma had traveled to the kingdom of Madra and bought with gold, the princess of that land. He presented the princess Madri to Pandu and the two were presently married. In the olden days, the kings took two or three wives to make sure they had progeny and not for any sensual pleasure.

Pandu and his two queens lived happily in Hastinapura for many months.
One day, when Pandu went hunting, he spied two deer copulating and let loose his arrows. The doe died immediately but the stag, fatally wounded, retained enough life to ask him why he had killed it.
``I am king,'' replied Pandu, ``surely I am allowed to hunt in my own forests?''
``It is not for your hunting that I blame you,'' grieved the deer, ``but that you should cruelly bring me grief at the moment of ecstasy.''
``Since you have made my love useless,'' continued the deer, ``so shall yours be. When you next make love, you shall die.'' With this curse, the deer breathed its last.
Pandu was terrified. He called his wives, told them about the curse and told them that he would retire to the forest. He told them to return to the city but his wives would not hear of it. Pandu sent the royal crown to Hastinapura and went with Kunti and Madri to a valley in the Himalayas where the three spent many peaceful months.

Pandu was inconsolable at the turn of events, since he could have no children. Kunti then confided in him the boon that she had gotten from the sage Durvasa 

By the sage's mantra, Kunti could call on any god she wished and the god would come and make love to her. Pandu brightened up. ``Call on the Lord Dharma,'' he ordered. The god of justice came down from heaven and of this coupling was born the Pandava, Yudhishthira. The son of Dharma would never stray from the truth.
``Call on the god Vayu,'' ordered Pandu. Kunti chanted her mantra and the god of the wind came down from heaven to give her a son, Bhima. Bhima's strength was to be unparalleled.
Madri saw her husband's first wife blessed with children and she too wanted a child. Pandu agreed but told them that it would be enough if they would each use it just once. Kunti called on Indra next. Indra gave her Arjuna, whose skill in weapons would be unmatched.
Madri noticed that Kunti had three sons. Yet, by her husband's orders, she could use the mantra just once. She called the Aswins, the twins who were physicians to the gods. Together, they came to Madri and gave her two sons - Nakula and Sahadeva.

Pandu was happy as he watched his sons grow. Yudhishthira, the son of Dharma, was their natural leader; Bhima was the strongest; Arjuna, the dark one, was gung-ho. The twins were handsome and care-free.

The deer's curse was fading from all their memories. One day, Pandu stalked Madri as she went to bathe in the forest and the two of them, caught in the throes of passion, forgot the curse. As he entered her, Pandu fell dead. Madri, feeling responsible for her husband's death, joined him in heaven .Two Nagas found their bodies in the forest and took the news to Kunti. They then escorted Kunti and the five Pandavas to Hastinapura.