Language change has been studied all over the world for several centuries, from the period of Classical Antiquity up to the Present-Day. In its primitive form, Historical Linguistics was studied by the Romans and the Ancient Greeks, who tried to reconstruct the origin of foreign words in their own languages.
In the last two centuries, Historical Linguistics has received more attention from German, English and French scholars.
Classical Antiquity (approximately 5th century B.C. – 5th century A.D.): some contributors were Plato, Herodotus, Varro and Quintilian. These thinkers, rather than approacing Historical Linguistics as a science, studied it in a more philosophical way, according to the customs of their times.
The Middle Ages (from around 410 A.D. to 1492 A.D.): amongst the most famous scholars are Donatus, Prician, Tatwine, Boniface, Bede and Ælfric. The majority of these authors, however, focussed mainly on the study Latin and (partially) Ancient Greek, which were used by the Church for religious and communicative purposes. Little attention was paid to scholarly improvements during the Middle Ages, due to the crisis caused by the fall of the Roman Empire.
The Renaissance and after (approximately from 1492 A.D. to the 17th century): some important figures in this period were Girolamo Aleandro, Aldus Manutius and Pierre Ramée. The Renaissance saw the revival of learning and therefore, scholarly advancements in the field were increasingly more common.
The Modern Period (from around the 17th century to the present times): the most important figures are William Jones, Philip Vezdin, Jacob Grimm, Wilhelm von Humboldt and Henry Sweet. This period saw scholarly advancements in the field of Philology, especially with regard to the study of Ancient languages such as Old English, Sanskrit and so on.
Nowadays, this field is constantly expanding and many more world-leading scholars are contributing to it. We can for example cite Richard Hogg and David Denison (as well as The University of Sheffield’s Mark Faulkner and Graham Williams!)