 Fortification had briskly increased in Gaul during the Viking Age (see Edict of Pistres) and this merely continued apace while the Carolingian dynasty declined in importance and regional control devolved to regional lords.In Languedoc and the south of France, there were more serious attempts, the Peace and Truce of God movements, to curb feudal warfare.But with the spread of heresy came the spread of castles as fortresses to which heretic barons could flee, such as the "five sons of Carcassonne."