Joret line


The Joret line is an isogloss used in the linguistics of the langues d'oïl. Dialects North and West of the line have preserved Vulgar Latin and before ; dialects South and East of the line have palatalized and before. This palatalization gave Old French and, then modern French and. The line was first identified by Charles Joret and published in 1883.
To the North and West of the line lie the Picard language and some dialects of the Norman language. To the South and the East lie other Oïl dialects including southern Norman, Walloon and French. The area North and West of the ligne Joret is sometimes called the Normano-Picard domain.

Geography

The Joret line extends from the Channel Islands and across the continent from Granville, Manche to the linguistic border with the Dutch language in the North of France and Belgium. It runs approximately West to East through Normandy north of Granville and Villedieu-les-Poêles and divides Manche in two linguistically and separates Calvados and Orne along with Eure; then it curves progressively to the North and ends up approximately South to North in Picardy, where the line runs with the Amiénois and Thiérache, up to the west of Rebecq, Beaumont and Chimay in Belgium where it separates Picard from Walloon.

Examples

Another effect of the palatalizations a bit further to the north but quite parallel was this:
A third isogloss, marking a consonantal change unrelated to the others, more or less follows the Joret line throughout Normandy and continues through northeastern France. It includes all of Picardy, Wallonia, Champagne, Lorraine and a part of Burgundy.
Germanic /w/ was kept north of the line, but became /g/ south of the line.
The Joret line affects toponyms in Normandy and Picardy: Cambrai, Camembert, Carentan, Caen.
Norman placenames derived from the Gallo-Romance word Campaniacum show initial C- in some cases and initial Ch- in others.