Wool Serge is woven in England in a simple left hand twill, from soft woollen yarn. Once a French term for twilled fabric woven in English-controlled Calais using British wool, it was similar to the 15th Century British Saye fabric, a lighter weight twilled cloth woven in the South West of England. Serge de Nîmes is the much-storied twilled cloth from Nîmes said to be the etymological origin of denim.