He was a spiritual writer. He worshipped Saiva Siddantha. He got married when he was sixteen. He attained Mukthi Motcha at the age of eighteen. Therefore, he had no children.
Karunai Prakasar was born in the town of Kanchipuram, Thondai Mandalam in Tamil Nadu, South India into an orthodox Saiva Tamil (Desikar) family around the middle of the 17th century. Karunai Prakasar's father, Kumara swamy Desikar, was a respectable spiritual leader. He was the Archaka and Dikshithar for the people of Thondai Mandalam. His father left his family and gone to Thiruvannamalai with his disciples. There he planned to become a Sage, but failed to do so. God made him get married. He got three sons and a daughter. Karunai Prakasar is the second child, and his siblings included Siva Prakasar, Velaiyar, and Gnambikai ammal . Siva Prakasar, his elder brother, the poet who was blessed as ‘Sivanuputhichelvar’ by the grace of God. He is acclaimed as ‘Karpanai Kalangiyam’ by renowned scholars of Tamil – speaking world. He compiled " Neerotta Yamaha Anthathi " to defeat the arrogant Poet. The verses will not make both lips touch. And also written " Yesu Matha Niragaranam " (The Refuting the Religion of Jesus). He attained Mukthi Motcha at the age of 32 age in Nallathur, near Pondicherry.
His sister Gnambikai married Perur Santhalinga Swamigal.
His younger brother, Velaiyar married Meenatchi Ammal . He had a son named Sundaresanar.
Velaiyar wrote more than seven books. Mayilathula, Nallur puranam, Mayilai thirattai mani maalai, Ishta linga kaithala maalai, Kumbakona Sarangathevar history as Veera singhathana puranam, Gugai Namachivaya Desikar history as Namchivaya leelai and Krisnanan history as Paarijatha leelai. And attained Mukthi Motcha at Perumathur at the age of seventy two.
Sundresanar married Karpagammal . He settled down his family in Valavanur. They got a son named Swaminatha Desikar.
Swaminatha Desikar converted himself to Christianity, changed his name as Susai Alias Swaminatha Desikar and married Gnasounthari.
Along with his Elder brother Sivaprakasa swamigal, travelled widely all over Tamil Nadu, famous temples like Thiruvannamalai, Thiruchendur ...
On one of his journeys around Tamil Nadu Sivaprakasa Swamigal, Karunai prakasar and velaiyar went to Tirunelveli to meet and be taught by a pandit Valliyur Thambiran, who was an expert on grammar. This teacher accepted them as his student. Karunai prakasar learnt Tamil grammar along with his brothers.
After that, he married Kamatchi . He wrote Tamil books along with his brothers.
He attain mukthi motcha in Thiruvengai at the age of Eighteen. His Elder brother Siva prakasa Swamigal and younger brother came to see his graveyard. There they, wrote few poems about his life style . And admired his Poetic service for Tamil. Later Velaiyar completed few of his unfinished writings.
He wrote more than five books.Seegalathi sarukkam l