 Secular topics were popular and included treatises on poetry ("Sringararatnakara") and writings on natural sciences ("Rattasutra"), mathematics ("Vyavaharaganita"), fiction ("Lilavati"), grammar ("Shabdamanidarpana"), rhetoric ("Udayadityalankara") and others.Important contributions were made by some prominent literary families.One Jain family produced several authors, including Mallikarjuna, the noted anthologist (1245); his brother-in-law Janna (1209), the court poet of King Veera Ballala II; Mallikarjuna's son Keshiraja (1260), considered by D. R. Nagaraj, a scholar on literary cultures in history, to be the greatest theorist of Kannada grammar; and Sumanobana, who was in the court of King Narasimha I and was the maternal grandfather of Keshiraja.