Before Kunti married Pandu, she bore Karna to Surya, the solar deity. Afraid of being an unwed mother, she placed the baby in a basket and set him afloat on a river. This child was later found and adopted by a chariot driver and his wife, and was named Karna. He went on to become a central character in the Mahabharata. The ambiguous emotions Karna felt about his birth mother play an important role in the Mahabharata. She later married Pandu and bore Yudhisthira,Bhima and Arjuna.They came to known as Pandavas,the sons of Pandu in the epic Mahabharata.After the death of her husband, Kunti did not commit sati, but his other wife Madri did. Kunti took care of Nakula and Sahadeva, the sons of Madri, as her own sons.Kunti also went into hiding with her sons after Duryodhana ,Shakuni tried to kill them all by burning them in Lakshagrah. Kunti prevented Bhima from killing the demoness Hidimba and advises him to marry her and beget Ghatotkacha. She instructed her children to take care of the common people and ordered Bhima to kill the demon Bakasura.
As war approached, Kunti met Karna and in desperation to keep her children alive asked Karna to join the Pandavas. But Karna denies the offer again.Knowing that Karna will fight against Arjuna with a motive to kill, Kunti extracted couple of promises from Karna that he will not kill any of the Pandavas except Arjuna and against Arjuna he will not use a same celestial weapon twice. This particular request by Kunti as suggested by Lord Krishna led to the death of Karna in the war as he did not use Nagastra and Rudraastra twice against Arjuna. Lord Krishna knew that Lord Parashurama gifted entire celestial weapons to Karna and Arjuna don't have any counter to many of these weapon. Karna requested his mother to keep their relationship a secret till the end of the war, as pandavas will not fight against their own brother in the Dharma Yuddha if she reveals the truth to them, due to dharma against fighting a brother/father figure. After the end of the war she is supposed to reveal his birth identity to everyone and also promised that at the end of the war she would still have five sons, the fifth one be either Arjuna or Karna himself.
^Kapoor, edited by Subodh (2002). The Indian encyclopaedia: biographical, historical, religious, administrative, ethnological, commercial and scientific (1st ed. ed.). New Delhi: Cosmo Publications. Page 7535.
^Krishna, the ultimate idol: [a provocative analysis of Krishna's life and mission] by Girīśa Pa Jākhoṭiyā
^"Kunti"(pdf). Manushi India Organization. Retrieved 10 January 2013.