Kumāradāsa is the author of a Sanskrit Mahākāvya called the Jānakī-haraṇa or Jānakī’s abduction. Jānakī is another name of Sita, wife of Rama. Sita was abducted by Ravana when she along with Rama, exiled from his kingdom, and Lakshmana was living in a forest which incident is taken from Ramayana ('Rama’s Journey'), the great Hindu epic written by Valmiki.
The Sinhalese translation of his work,Jānakī-haraṇa, gave credence to the belief that Kumāradāsa was King Kumāradhātusena (513-522 A.D.) of Sri Lanka but scholars do not make any such identification even though the poet at the end of his poem says that his father, Mānita, a commander of the rearguard of the Sinhalese King Kumāramaṇi, died in battle on the day he was born and that his maternal uncles, Megha and Agrabodhi, brought him up. Rajasekhara, who lived around 900 A.D., in his Kāvyamīmāmsā refers to the poet as born blind - मेधाविरुद्रकुमारदासादयः जात्यन्धाः. There is also a tradition that this poem was written by Kalidasa. Kumāradāsa came after Kalidasa and lived around 500 A.D., later than Bhāravi but before Māgha. While writing Jānakī-haraṇa, he certainly had before him Raghuvaṃśa of Kalidasa.
In his "Survey of Sanskrit Literature", about Kumāradāsa and Jānakī-haraṇa (20 Cantos), which poem the poet is believed to have written during his stay in Kanchipuram where he lived, C. Kunhan Raja Ph.D. says:
A verse in the Subhāṣita-ratna-kośa refers to Kumāradāsa's Jānakī-haraṇa:
jānakī-haraṇaṃ kartuṃ
raghuvaṃśe puraḥsthite /
kaviḥ kumāradāso vā
rāvaṇo vā yadi kṣamaḥ //
To have produced an Abduction of Sita,
When the Dynasty of Raghu was present before him —
One must have been Kumāradāsa
or else been Rāvaṇa.