I am herewith providing more details of the story of King Bhavya or King Swanaya mentioned in Rig-Veda mandala 1- Sukta 126. The story is present in both this as well as in previous sukta i.e. RV. 1.125.
King Bhava or Bhavayavya was a king who lived on the banks of the Indus,whose son was King Swanya Or Bhavya.
The Rishi of the Sukta 1.125 is Kakshivan Dharghatamas and Devata is Swanay Danastuti.
The Rishi of the Sukta 1.126 is Kakshivan Dharghatamas , Swanaya Bhavaya & Romasha and the Devata is Swanaya Bhavya .
Both Sukta 1.125 and 126 is mentioning the story. And the story is mentioned by Sayanacharya in his Rig-Veda bhashya translated by H.H.Wilson.
Now let's see what is the story mentioned by Sayana.
Brief of the story - Kakshivat is a Vedic sage . He was the son of Dirghatamas and Usij. He was also called Pajriya, because he was of the race of Pajra, means strong. He is the seer of hymns RV. 1.125 -126 he praises on the liberality of King Swanaya.
Kakshivat, finished his vedic study, took leave of his guru and left home. As he journeyed night came and he fell asleep by the roadside. In the morning he was awaken by king Swanaya, who, was impressed by his appearance, treated him in friendly way and took him home. After knowing Kakshivat's worthiness, he offered his ten daughters to Kakshivat in marriage. The king presented Kakshivat at the same time with a hundred nishkas of gold, a hundred horses, a hundred bulls, a thousand and sixty cows, and eleven chariots, one for each of his ten wives, and one for himself, each drawn by four horses. In return Kakshivat praise King Swanaya in a Vedic hymn.
Sayana's introduction Of Hymn RV.1.125 -:
This Hymn is supposed to be recited by Kakshivat , in the
acknow-ledgment of the liberality of Raja Swanaya ,whose gift is
therefore considered as the divinity of the hymn , or the object
Sayana's details about the story mentioned in RV. 1.125 .
The legend which is cited by Sayana and which is told to the like
purport in the "Niti-Manjari" relates that Kakshivat , having finished
his course of study and Kakshivat, took leave of his preceptor , was journeying homewards , when
night came on , and he fell asleep by the road-side: early in the
morning , Raja Swanaya , the son of Bhavayavya , attended by his
retinue, came to the spot , and disturbed the Brahmanas slumbers :
upon his starting up , the Raja accosted him with great cordiality ,
and being struck by his personal appearance , determined ,if he was
suitable rank and birth , to give him his daughters in marriage .
After ascertaining his fitness , he took Kakshivat home with him and
there married him to his ten daughters , presenting him at the same
time with a hundred nishkas of gold , a hundred horses , a hundred
bulls , one thousand and sixty cows , and eleven chariots , one for
each of his wives and one for himself , each drawn by four horses.
With this present Kakshivat returned home , and placed them atthe
disposal of his father Dirghatamas , reciting this Hymn in praise of
And here is what he says about Bhavya in RV.1.126
Bhavya is here identified evidently with Swanaya his son.
So Bhavya or Swanaya was the son of Bhava or Bhavayavya. His full name King Swanaya Bhawayabya . Romasha was said to be the daughter of Brihaspati and the wife of King Swanaya or Bhavya. .