De Viris Illustribus ("On Illustrious Men") is a collection of short biographies of 135 authors, written in Latin, by the 4th-century Latin Church Father Jerome, the book was dedicated to Flavius Dexter, who served as high chamberlain to Theodosius I and as praetorian prefect to which Western Roman Emperor from 393 to 423, the  younger son of emperor Theodosius I and his first wife Aelia Flaccilla, and brother of Arcadius?