In the Mahabharata, the story of Dushyanta, king of Hastinapur, and Shakuntala, daughter of Rishi Vishwamitra and the apsara (angel) Menaka, is described in the Adi Parva (Sambhava Upa-parva) section. Dushyanta is on a tour in the forest. He reaches Rishi Kanva’s hermitage where he encounters Shakuntala who is a great beauty. For the king, it is love at first sight. Here’s an excerpt from the exchange between Dushyanta and Shakuntala:
Dushyanta said to Shakuntala: “Marry me according to the Gandharva form, for this form of marriage is said to be the best.”
Shakuntala: “O king, my father has gone from the hermitage to collect fruits. Kindly wait for a moment. He will bestow me upon you.”
Dushyanta: “O beautiful lady, O faultless beauty, I desire you yourself should accept me. Know that I exist for you. Know also, my heart is completely in you, One is certainly one's own friend, one can certainly depend on one's own self, Therefore, according to the ordinance (scriptures), you yourself should bestow your own self on others.”
Dushyanta and Shakuntala have a Gandharva marriage (in Hindu law, Gandharva marriage is contracted by mutual consent and without formal rituals). Soon it is time for Dushyanta to leave for Hastinapur. Before departing, he gave Shakuntala his ring as a proof of their marriage, and promised that he would return to take her to his kingdom.
One day, Rishi Durvasa, known for his temper, arrives at the hermitage. Shakuntala was engaged in thinking about Dushyanta and she forgets to serve food to Durvasa. In a fit of anger, Durvasa cursed Shakuntala that the man, whose thoughts had filled her mind, would forget her. Shakuntala was shocked; she pleaded for mercy. Durvasa relented and proclaimed that her man would remember her when she showed him the proof of their marriage.
After that Shakuntala left for Hastinapur, carrying with her the ring that Dushyanta had given her. She hoped that Dushyanta would remember her when she showed him the ring. But on the way she had an accident and a fish swallowed the ring. Now Shakuntala had no proof of her marriage with Dushyanta. When she reached Dushyanta's court in Hastinapur, he could not recognize her. But a sage who had managed to recover the ring from the fish arrived at the king’s court. Once Dushyanta saw the ring, his memory was rekindled and he remembered Shakuntala.
There was a royal marriage between Dushyanta and Shakuntala, who became the queen of Hastinapur. Their son Bharata becomes the founder of the Kuru Dynasty and the ancestor of the Pandava and the Kaurava clans.