In French Gothic architecture, Rayonnant () is the period from about the mid-13th century to mid-14th century. It was characterized by a shift away from the High Gothic search for increasingly large size toward more spatial unity, refined decoration, and additional and larger windows, which filled the space with light. Prominent features of Rayonnant include development of the rose window; more windows in the upper-level clerestory; the reduction of the importance of the transept; and larger openings on the ground floor to establish greater communication between the central vessel and the side aisles. Interior decoration increased, and the decorative motifs spread to the outside, to the facade and the buttresses utilizing great scale and spatial rationalism towards a greater concern for two-dimensional surfaces and the repetition of decorative motifs at different scales. The use of tracery gradually spread from the stained glass windows to areas of stonework, and to architectural features such as gables. The first major example in France was Amiens Cathedral (1220–1270). The most prominent and accomplished French example was the rebuilding of portions of Notre Dame de Paris (begun 1250s), including the addition of the great rose windows. The finest example of the late Rayonnant is the royal chapel in Paris, Sainte-Chapelle, in which the upper floor has the appearance of a great cage of stained glass. From Medieval France, the style quickly spread to England, where French Rayonnant tracery was often incorporated into more traditional English features, such as colonettes and vault ribs. Notable examples of Rayonnant in England include the Angel Choir of Lincoln Cathedral, and that of Exeter Cathedral (begun before 1280). The striking retrochoir of Wells Cathedral (begun before 1280), the choir of Saint Augustine at Bristol Cathedral, and Westminster Abbey are other important examples. After the mid-14th century, Rayonnant was gradually replaced by the more ornate and highly decorated Flamboyant style. Name The term "Rayonnant" comes from the radiating spokes of the rose windows of the major cathedrals. In England, it is sometimes called the Decorated style. The term was first used by 19th-century French art historians (notably Henri Focillon and Ferdinand de Lasteyrie) to classify Gothic styles on the basis of window tracery. Rayonnant in France The origin of the Rayonnant style took place during the reign of Louis IX of France, or Saint Louis, who reigned from 1226 to 1270. During his reign, France was the wealthiest and most powerful