Long DescriptionEnglish Gothic architecture c. 1240-1290. During this period the French invention of bar tracery allowed for larger windows subdivided by stone mullions and tracery, in place of the single lancets of the Early English style. Geometrical tracery is the earliest kind of this bar tracery, i.e. with patterns formed by intersecting moulded ribwork continuing upwards from the mullions, using simple forms, especially circles, chiefly foiled.