The King of Vidarbha, Maharaja Bhismaka, was very qualified and devoted. He had five sons and only one daughter. The first son was known as Rukmi

Expressions researched:
"Rukmi was the first-born son" |"The King of Vidarbha, Maharaja Bhismaka, was very qualified and devoted. He had five sons and only one daughter. The first son was known as Rukmi"

Krsna, The Supreme Personality of Godhead

Krsna Book 52:

The story of Kṛṣṇa's marriage with Rukmiṇī is described as follows. The King of Vidarbha, Mahārāja Bhīṣmaka, was very qualified and devoted. He had five sons and only one daughter. The first son was known as Rukmī; the second, Rukmaratha; the third, Rukmabāhu; the fourth, Rukmakeśa; and the fifth, Rukmamālī. The brothers had one young sister, Rukmiṇī. She was beautiful and chaste and was meant to be married to Lord Kṛṣṇa. Many saintly persons and sages like Nārada Muni used to visit the palace of King Bhīṣmaka. Naturally Rukmiṇī had a chance to talk with them, and in this way she obtained information about Kṛṣṇa. She was informed about the six opulences of Kṛṣṇa, and simply by hearing about Him she desired to surrender herself to His lotus feet and become His wife.

SB Cantos 10.14 to 12 (Translations Only)

SB 10.52.21, Translation:

Śrī Bādarāyaṇi said: There was a king named Bhīṣmaka, the powerful ruler of Vidarbha. He had five sons and one daughter of lovely countenance.

SB 10.52.22, Translation:

Rukmī was the first-born son, followed by Rukmaratha, Rukmabāhu, Rukmakeśa and Rukmamālī. Their sister was the exalted Rukmiṇī.