The Joret line (Norman: lène Joret: Picard: line Joret) is an isogloss that divides the langues d'oïl. Dialects north and west of it preserve Latin and before ; dialects south and east of it palatalize them. In Old French the result of this palatalisation was and (for original and respectively), which yield and in Modern French. The line was first identified by Charles Joret and published in 1883. The area north and west of it is sometimes called the 'Normano-Picard domain'. Within it lie Picard and the northern dialects of Norman.

Geography

The Joret line extends from the Channel Islands (including Jèrriais, Guernésiais, and Sercquiais) and across the continent from Granville, Manche to the linguistic border with Dutch 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

Second isogloss

Another effect of the palatalizations a bit further to the north but quite parallel was this:

Third isogloss

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 (sometimes Latin was affected as well) was kept north of the line (written w or v), but became (written g or gu) south of the line.

Toponymy

The Joret line affects toponyms in Normandy and Picardy: Cambrai (corresponding to Chambray), Camembert, Carentan (corresponding to Charenton), Caen (Wace gallicized as Chaem). Norman placenames derived from the Gallo-Romance word Campaniacum show initial C- in some cases (Campigny, north) and initial Ch- in others (Champigny-la-Futelaye, south).