Kesari was a forest King who lived in the Maha Meru. While Kesari was living in the Mahameru, Brahma cursed a celestial maid named Managarva and changed her into a female monkey. She became the wife of Kesari, under the name Anjana. For a long time the couple had no children. Anjana worshipped Vayu Bhagavan (Wind-God) for a child.
The full story of Kesari, the father of Hanuman, in Isvara Archive.