Isidore was widely read, mainly in Latin with a little Greek and Hebrew. He was familiar with the works of both the church fathers and pagan writers such as Martial, Cicero and Pliny the Elder, this last the author of the major encyclopaedia then in existence, the "Natural History". The classical encyclopedists had already introduced alphabetic ordering of topics, and a literary rather than observational approach to knowledge: Isidore followed those traditions. Isidore became well known in his lifetime as a scholar. He started to put together a collection of his knowledge, the "Etymologies", in about 600, and continued to write until about 625.