Akrūra happened to be one of the cousins of Kuntī; therefore, after meeting him, she began to inquire about her paternal relatives. Thinking of her birthplace and beginning to cry, she asked Akrūra whether her father, mother, brothers, sisters and other friends at home still remembered her. She especially inquired about Kṛṣṇa and Balarāma, her glorious nephews. She asked, "Does Kṛṣṇa, the Supreme Personality of Godhead, who is very affectionate to His devotees, remember my sons? Does Balarāma remember us?" Inside herself, Kuntī felt like a she-deer in the midst of tigers, and actually her position was like that.
(Krsna Book).

After hearing this statement, Akrūra could clearly understand that Dhṛtarāṣṭra was not going to change his policy of discriminating against the Pāṇḍavas in favor of his sons. He at once took leave of his friends in Hastināpura and returned to his home in the kingdom of the Yadus. After returning home, he vividly informed Lord Kṛṣṇa and Balarāma of the actual situation in Hastināpura and the intentions of Dhṛtarāṣṭra. Akrūra was sent to Hastināpura by Kṛṣṇa to study these, and by the grace of the Lord he was successful.
(Krsna Book).

While Lord Kṛṣṇa was thinking in that way, two beautiful chariots, fully equipped with drivers, weapons, flags and other paraphernalia, arrived for Him from outer space. Kṛṣṇa saw the two chariots present before Him and immediately addressed His elder brother, Balarāma, who is also known as Saṅkarṣaṇa: "My dear elder brother, best among the Āryans, You are the Lord of the universe, and, specifically, You are the protector of the Yadu dynasty. The members of the Yadu dynasty sense great danger before the soldiers of Jarāsandha, and they are very much aggrieved. Just to give them protection, Your chariot is also here, filled with weapons. I request You to sit on Your chariot and kill all these soldiers, the entire military strength of the enemy. The two of Us have descended to this earth just to annihilate such unnecessary bellicose forces and give protection to the pious devotees. So we have the opportunity to fulfill Our mission. Please let Us execute it." Thus Kṛṣṇa and Balarāma, the descendants of Daśārha, decided to annihilate the thirteen military companies of Jarāsandha.
(Krsna Book).

After equipping Themselves with military dress, Kṛṣṇa and Balarāma mounted Their chariots. Kṛṣṇa rode the chariot of which Dāruka was the driver. With a small army They came out of the city of Mathurā, blowing Their respective conchshells. Curiously enough, although the other party was equipped with greater military strength, when they heard the vibration of Kṛṣṇa's conchshell their hearts were shaken. When Jarāsandha saw Balarāma and Kṛṣṇa, he was a little bit compassionate because They happened to be related to him as grandsons. He specifically addressed Kṛṣṇa as puruṣādhama, meaning "the lowest among men." Actually Kṛṣṇa is known in all Vedic scriptures as Puruṣottama, the highest among men. Jarāsandha had no intention of addressing Kṛṣṇa as Puruṣottama, but great scholars have determined the true meaning of the word puruṣādhama to be "one who makes all other personalities go downward." Actually no one can be equal to or greater than the Supreme Personality of Godhead.
(Krsna Book).

Jarāsandha said, "It will be a great dishonor for me to fight with boys like Kṛṣṇa and Balarāma." Because Kṛṣṇa had killed Kaṁsa, Jarāsandha specifically addressed Him as the killer of His own relatives. Kaṁsa had killed many of his own nephews, yet Jarāsandha did not take notice, but because Kṛṣṇa had killed His maternal uncle, Kaṁsa, Jarāsandha tried to criticize Him. That is the way of demoniac dealings. Demons do not try to find their own faults or those of their friends, but try to find the faults of their enemies. Jarāsandha also criticized Kṛṣṇa for not even being a kṣatriya. Because He was raised by Mahārāja Nanda, Kṛṣṇa was not a kṣatriya but a vaiśya. Vaiśyas are generally called guptas, and the word gupta can also be used to mean "hidden." So Kṛṣṇa was both hidden and raised by Nanda Mahārāja.
(Krsna Book).

Jarāsandha accused Kṛṣṇa of three faults: that He killed His own maternal uncle, that He was not even a kṣatriya, and that He was hidden in His childhood. And therefore Jarāsandha felt ashamed to fight with Him.
Next he turned toward Balarāma and addressed Him: "You, Balarāma! If You like You can fight along with Him, and if You have patience, then You can wait to be killed by my arrows. Thus You can be promoted to heaven." It is stated in the Bhagavad-gītā that a kṣatriya can benefit in either of two ways while fighting. If a kṣatriya gains victory in the fight, he enjoys the results of victory, but even if killed he is promoted to the heavenly kingdom.

(Krsna Book).

As the sun appears covered by cloudy air and dust, Kṛṣṇa, the supreme sun, was covered by the military strength of Jarāsandha. Kṛṣṇa's and Balarāma's chariots were marked with pictures of Garuḍa and palm trees, respectively. The women of Mathurā all stood on the tops of the houses, palaces and gates to see the wonderful fight, but when Kṛṣṇa's chariot was surrounded by Jarāsandha's military force and was no longer visible to them, they were so frightened that some of them fainted. Kṛṣṇa saw Himself overwhelmed by the military strength of Jarāsandha. His small army of soldiers was being harassed, so He immediately took up His bow, named Śārṅga.

(Krsna Book).

Lord Balarāma, who is also known as Saṅkarṣaṇa, began to fight with His club in such a heroic way that the river of blood created by Kṛṣṇa overflooded. Cowards became very much afraid upon seeing the ghastly and horrible scene, and heroes began to talk delightedly among themselves about the heroism of the two brothers. Although Jarāsandha was equipped with a vast ocean of military strength, the fighting of Lord Kṛṣṇa and Balarāma converted the whole situation into a ghastly scene far beyond ordinary fighting.

(Krsna Book).

Persons of ordinary merit cannot estimate how it could be possible, but when such activities are accepted as pastimes of the Supreme Personality of Godhead, under whose will everything is possible, then this can be understood. The Supreme Personality of Godhead creates, maintains and dissolves the cosmic manifestation merely by His will. For Him to create such a vast scene of devastation while fighting with an enemy is not so wonderful. And yet, because Kṛṣṇa and Balarāma were fighting with Jarāsandha just like ordinary human beings, the affair appeared wonderful.

(Krsna Book).

When all the soldiers of Jarāsandha had been killed and he was the only one left alive, certainly he was very much depressed. Śrī Balarāma immediately arrested him with great strength, just as one lion captures another. But while Lord Balarāma was binding Jarāsandha with the rope of Varuṇa and ordinary ropes also, Lord Kṛṣṇa, with a greater plan in mind for the future, asked Lord Balarāma not to arrest him. Kṛṣṇa then released Jarāsandha. As a great fighting hero, Jarāsandha was ashamed, and he decided that he would no longer live as a king but would resign from his position in the royal order and go to the forest to practice meditation under severe austerities and penances.

(Krsna Book).

When Lord Kṛṣṇa was entering the nicely decorated city of Mathurā in a festive attitude, the ladies and girls of Mathurā prepared different kinds of flower garlands to make the ceremony most auspicious. In accordance with the Vedic custom, they took yogurt mixed with fresh green grass and strewed it here and there to make the victory jubilation even more auspicious. As Kṛṣṇa passed through the street, all the ladies and women regarded Him with eyes bright with great affection. Kṛṣṇa and Balarāma carried various kinds of ornaments, jewels and other booty carefully collected from the battlefield and presented it all to King Ugrasena. Kṛṣṇa thus offered His respect to His grandfather because Ugrasena was at that time the crowned king of the Yadu dynasty.

(Krsna Book).

When Mathurā was thus besieged, Lord Śrī Kṛṣṇa began to consider, in consultation with Baladeva, how much the Yadu dynasty was in distress, being threatened by the attacks of two formidable enemies, Jarāsandha and Kālayavana. Time was growing short. Kālayavana was already besieging Mathurā from all sides, and it was expected that the day after next, Jarāsandha would also come, equipped with the same number of divisions of soldiers as in his previous seventeen attempts.

(Krsna Book).

Kṛṣṇa was certain that Jarāsandha would take advantage of the opportunity to capture Mathurā when it was also being besieged by Kālayavana. He therefore thought it wise to take precautionary measures for defending against an attack upon Mathurā from two strategic points. If both Kṛṣṇa and Balarāma were engaged in fighting with Kālayavana at one place, Jarāsandha might come at another to attack the whole Yadu family and take his revenge.

(Krsna Book).

When the new city was fully constructed according to plan, Kṛṣṇa transferred all the inhabitants of Mathurā and installed Śrī Balarāma as the city father. After this He consulted with Balarāma, and, being garlanded with lotus flowers but carrying no weapons, He came out of the city to meet Kālayavana, who had already surrounded Mathurā.

(Krsna Book).

This time, Jarāsandha thought that Kṛṣṇa and Balarāma were very much afraid of his military strength and were fleeing the battlefield. He followed Them with all his chariots, horses and infantry. He thought Kṛṣṇa and Balarāma to be ordinary human beings, and he was trying to measure the activities of the Lord. Due to this pastime Kṛṣṇa is known as Raṇacora, which means "one who has left the battlefield."

(Krsna Book).

As the fire spread more and more, Kṛṣṇa and Balarāma jumped from the top of the mountain down to the ground—a distance of eighty-eight miles. Thus, while the peak was burning up, Kṛṣṇa and Balarāma escaped, unseen by Jarāsandha or his men. Jarāsandha concluded that the two brothers had burned to ashes and that there was no need of further fighting. Thinking himself successful in his efforts, he left the city of Mathurā and returned to his home in the kingdom of Magadha. Gradually Kṛṣṇa and Balarāma reached the city of Dvārakā, which was surrounded by the sea.

(Krsna Book).

Following this, Śrī Balarāma married Revatī, daughter of King Raivata, ruler of Ānarta Province. This is explained in the Ninth Canto of Śrīmad-Bhāgavatam. After the marriage of Baladeva, Kṛṣṇa married Rukmiṇī. Rukmiṇī was the daughter of King Bhīṣmaka, ruler of the province known as Vidarbha. Just as Kṛṣṇa is the Supreme Personality of Godhead, Vāsudeva, Rukmiṇī is the supreme goddess of fortune, Mahā-Lakṣmī. According to the authority of the Caitanya-caritāmṛta, the expansion of Kṛṣṇa and that of Śrīmatī Rādhārāṇī are simultaneous: Kṛṣṇa expands Himself into various viṣṇu-tattva forms, and Śrīmatī Rādhārāṇī expands Herself into various śakti-tattva forms, by Her internal potency, as multiforms of the goddess of fortune.

(Krsna Book).