Madri was a princess of the Madra kingdom and the second wife of Pandu.
On his way to Hastinapur, King Pandu encountered the army of Shalya, King of Madra. Very soon, Pandu and Shalya became friends and Shalya gave his only sister, Madri to Pandu, as a gift of their friendship. Looking at her beauty, Pandu accepted the lady willingly and took her to Hastinapur.
She, alongside Kunti, faithfully accompanied Pandu in his hermetical retreat following his abdication as the king of Hastinapura. Both Kunti and Madri were directly affected by the curse on Pandu because they were denied the opportunity to bear Pandu's children. However, a boon was given to Kunti which enabled her to bear Yudishtira, Bhima, and Arjuna. This boon was passed on to Madri, who then bore twins from Ashwins named Nakula and Sahadeva. Madri apparently made a misuse of the boon. The boon was to be used only with a single God (the word God being used loosely) at a time and Madri invoked the presence of twin Gods (the Ashwin twins). Hence Kunti took the boon back from Madri.
One fateful day, Pandu desired Madri and the memory of the curse briefly eluded him. Death struck Pandu immediately. Madri, filled with remorse, self immolated on Pandu's funeral pyre. Kunti became a single mother of the five children.