The author of the play/book ?Ratnawali

Ratnawali was a Sanskrit play written by Emperor Harsha (Harsha Vardhan), who ruled in the 7th century CE. Harsha was not only a capable ruler but also a patron of arts and literature, composing three plays: Ratnavali, Priyadarshika, and Nagananda. Tulsidas wrote Ramcharitmanas much later (16th century), Kalidasa was a classical Sanskrit poet from the Gupta period (4th-5th century), and Premchand was a modern Hindi-Urdu writer (20th century).