Wikipedia
Vishrava was the son of Pulastya and the grandson of Brahma, the Creator, and a powerful Rishi as described in a scripture epic of Ancient India. A scholar par excellence, he earned great powers through Tapasya, which in turn, earned him great name and fame amongst his fellow Rishis. Bharadwaja, in particular, was so impressed with Vishrava that he gave him his daughter, Ilavida, in marriage. Ilavida bore Vishrava a son, Kubera, the Lord of Wealth and the original ruler of Lanka.
The accounts of Vishrava's far-reaching Yogic powers reached the ears of the Asura, Sumali, and his wife, Tataka. Both sought to increase their own powers through alliances with mighty Kings and Rishis. They decided that their daughter, Kaikesi would make a worthy wife for Vishrava and orchestrated her chance encounter with the Rishi. Vishrava fell in love with the beautiful Kaikesi and fathered four children with her. The oldest was Ravana who would eventually oust his half-brother, Kubera, as King of Lanka and usurp his throne. Ravana was also the villain of the immortal epic, the Ramayana.
In addition to Ravana, Vishrava fathered Vibhishana, Kumbakarna and a daughter, Soorpanaka, through Kaikesi. He is said to have disowned his demonic family after witnessing Ravana's disrespectful treatment of his older brother, Kubera and returned to his first wife, Ilavida.
According to the Mahabharata, however, Vishrava's younger children were born as a result of a falling-out with his eldest: Kubera tried to placate his father by giving him three Rakshasis (two of whom, Raka and Pushpotkata/Pushpotata, seem to be Kaikesi's paternal half-sisters) and in due course Vishrava impregnated all three of them. Pushpotata gave birth to Ravana and later to Kumbhakarna, Malini bore Vibhishana, and Raka had the unpleasant and unsociable twins Khara and Shurpanakha.