BYZANTINE AND ROMANESQUE ARCHITECTURE) poured on the West a stream of versatility and imagination more particularly reflected in the lavish use of strongly coloured mosaics. Ravenna still represents a glorious contribution to the history of the use of that particular medium. Further east, China had for centuries produced works of art in painting, sculpture and architecture (see CHINESE ARCHITECTURE) which were particularly notable in the epochs marking a lull in European cultural activity. The Mongol invasion of the 12th century had done more than conquer Persia and its great empire. Chinese forms, decorative motifs, were promptly absorbed in Persian decoration and some of the influ ence of China through Persia found its way to Spain. India like wise had developed a rich heritage of architecture (see INDIAN