The existence of the Ravenna School of Medicine can be deduced from a codex in the Ambrosian Library of Milan, which contains Latin translations of 3 Hippocratic works and commentaries on 4 works by Galen. Although it was written in the 9th century, the codex appears to be a copy of an earlier work, probably 7th century. The Ambrosian commentaries follow other commentators on Aristotle, rather than the original Aristotelian works, and contain a number of misinterpretations. Nevertheless, the commentaries make it clear that the earliest literature in Salerno had its roots in the studies of classical medicine at the Ravenna School of Medicine, where the teaching was essentially Galenic in structure.