Diez, Friedrich Christian, a German philologist, born at Giessen; after service as a volunteer against Napoleon, and a tutorship at Utrecht, went to Bonn, where, advised by Goethe, he commenced the study of the Romance languages, and in 1830 became professor of them, the philology of which he is the founder; he left two great works bearing on the grammar and etymology of these languages (1794‒1876).
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Dietrich of Bern * Diez, Juan Martin