Arjuna sees Subhadra at the Raivataka festival; Krishna advises him to carry her off rather than risk a swayamvara; the Yadavas rush to arms and Balarama rages until Krishna persuades them to bring Arjuna back for the wedding. The Bhagavata has Arjuna come as an ascetic, Subhadra want him too, and her parents agree.
Mahabharata, Adi Parva, sections 220 to 223 (Ganguli)
West India · Raivataka and DwarakaAll traditions
Arjuna, on a long journey away from his brothers, meets Krishna at Prabhasa and goes with him to Dwaraka. At a festival of the Yadavas on Raivataka hill he sees Subhadra among her companions and is smitten. Krishna, smiling, tells him she is his sister Bhadra, Sarana's own sister and their father's favourite, and offers to speak to his father; but since no one knows whom a girl will choose at a swayamvara, and carrying off a bride is praised for brave warriors, he advises Arjuna to take her by force. Yudhishthira consents by messenger. Arjuna, in armour on a golden chariot drawn by Saivya and Sugriva, seizes her as she comes back from worship on the hill. Her guards raise the alarm in the Sudharma hall; the clan runs for weapons; Balarama, in blue, stops them until Krishna speaks, then vows to rid the earth of the Kurus. Krishna answers that Arjuna knows they do not sell daughters, thought a swayamvara uncertain, is of a great line and unbeatable but for Shiva, and should be brought back kindly. They bring him back; he marries her at Dwaraka and stays a year. At Indraprastha she bows to Kunti and to Draupadi in a cowherd woman's dress, and Draupadi blesses her. Krishna and Balarama bring the wedding gifts, and Abhimanyu is born.
At Prabhasa Arjuna hears that Balarama means to give Subhadra to Duryodhana, against everyone else's wish. He comes to Dwaraka as a wandering ascetic with a triple staff and stays through the rains, honoured by Balarama and the citizens, who do not know him. Balarama has him to dine, and there he sees Subhadra; she wants him too, and shows it with shy smiles and glances. At a great festival procession of the Lord she rides out of the fortress, and he carries her off, with the consent of her parents and Krishna, driving off the guards with his bow. Balarama heaves like the sea at the full moon; Krishna takes hold of his feet and the kinsmen calm him, and he sends elephants, chariots, horses and servants as wedding gifts.
Sources: Mahabharata, Adi Parva, Subhadra-harana and Haranaharana Parvas, sections 220 to 223, tr. K. M. Ganguli; Srimad Bhagavatam 10.86.1 to 12 (Bhaktivedanta Book Trust)