By the 13th century the Gothic was the only style of building throughout northwestern Europe. The designs of vaulting, buttresses, and windows first produced by Gothic architects were imitated by other artists. The pointed arch is found again and again as a frame for paintings and ivory carvings. It is stamped on book covers and worked in metal for caskets and shrines. As time went on, the details of Gothic style developed and changed, first in the greater buildings and later in the smaller works of art.
The earliest Gothic windows had been narrow, but with a pointed instead of a round top. Then they became so large that it was necessary to put stone supports inside them to hold the glass firmly. These supports formed smaller pointed arches, circles, cloverleafs, and more complicated shapes. The stone patternwork inside each window is known as tracery.
Tracery, a typically Gothic form, was used at Reims (Rheims) Cathedral in 1211 or 1212 by the mason Jean d'Orbais. Reims Cathedral was the church where the coronations of French kings took place. It was this important royal connection that gave the new window tracery of Reims its great prestige.
While Reims Cathedral was being built it was visited by many architects. Impressed by the beauty of the new Gothic tracery, they made sketches of it. Among these architects was Villard de Honnecourt, whose sketchbook can still be seen in the National Library in Paris. Honnecourt thought that the Reims windows were the most beautiful he had seen anywhere--and he had traveled across Europe through Switzerland and Germany and as far as Hungary. Other architects at the time were making sketches too, and the idea of tracery spread to many distant places.
Tracery may have been introduced to England by an architect called Master Henry, who had worked at Reims and who became the chief architect to King Henry III. He used tracery for the windows of Westminster Abbey, which he designed in 1245. Here the kings of England were to be crowned and buried. The new fashion was approved by the English king and was quickly adopted across the country. In France traceried windows like those at Reims were called the style rayonnant ("radiant style"). This term was used to describe a style of decorative art that was based on tracery. It referred, however, to decorative objects as well as to windows. Many people think that it represents the highest development of Gothic style.
To this flowering of the Gothic belong the famous French cathedrals of Reims, Amiens, and Beauvais, in the north, while the same style was carried down to the south, through Limoges and Rodez to Narbonne.
During the Middle Ages many artists moved from place to place and from country to country, all over Europe, taking with them the latest ideas and the newest fashions in art. In Spain the style rayonnant influenced the design of the cathedral of Leon. There most of the glorious colored glass designed and made for the traceried windows still survives. In Germany, Cologne Cathedral was begun in 1245, but it was not finished for more than 600 years. French masons, under the architect Étienne de Bonneuil, were called far away to Uppsala, in Sweden, to design the cathedral that was built between 1270 and 1315.