In the course of researching my Chastain family, I’ve stumbled upon an excellent online dictionary of French surnames.
The entry for Chastang translates roughly to the following:
Worn in the Cantal, Corrèze and Lozère, it is a toponym evoking the chestnut tree (Occitan “castanh”). Variants or similar forms: Chastain, Chastaing, Chastaingt, Chastan, Chastand, Chastant, names all encountered in the northern part of the Occitan domain, from the Dordogne to the Drôme.
The Drôme, the area mentioned at the end of the entry, is where Vesc, ancestral village of the Chastains, is located. Chastain is a toponym, a type of surname derived from a feature in the local environment, typically near where the person who was given the surname lived. In the case of Chastain, the name would have been given to someone who lived near a prominent chestnut tree.
Occitan, mentioned in the entry, is a Romance language still spoken in the south of France. This was the language of the medieval troubadours and, centuries ago, was widely known even outside of France. Like any other language, Occitan has several dialects. A feature of the Vivaro-Alpin dialect, spoken in northern parts of southern France, such as the Drôme, is a soft ‘ch’ sound instead of a hard ‘c’. This would seem to explain the evolution of the Latin word for chestnut, castanea, with its hard ‘c’, to chastain and its variants, with their soft ‘ch’, in French (like the ‘ch’ in champagne i.e. an English ‘sh’ sound).
Switching gears, another resource that’s been helpful in my research is this Dictionary of Middle French. In the course of translating historical documents, I often give this a try if the translation into Modern French isn’t making sense. It’s clarified quite a few passages that were previously impenetrable.
Finally, moving even further into the past, the Etymological Dictionary of Old French is another fascinating resource. (I think I was a linguist in another life). It details different spellings of words in Old French and, citing original medieval texts, gives examples of each spelling variant. This dictionary led me to an old 12th century manuscript titled Liber de simplici medicina. In it, a reference is made to miel chastain, a cold remedy consisting of honey infused with a bitter chestnut flour.
I’m tickled to see my surname, spelled exactly how it is today, in a text that’s over eight hundred years old. The word chastain, having evolved into other forms, hasn’t been a part of the French language for centuries, making my surname, Chastain, a fossilized record of an ancient, extinct word.