Handwritten manuscripts that have been decorated with gold or silver, brilliant colors, designs, or miniature pictures. Although prevalent in Islamic and Asian societies, the longest tradition of illuminating manuscripts was in Christian medieval Europe, from the 6th-16th centuries, when the art was superseded by printed illustrations. Generally, the manuscripts were both 'historiated', or decorated with relevant paintings, and 'illuminated' in its original sense, meaning decorated with calligraphic initial capital letters using gold leaf. Over time, the term 'illuminated' came to refer to any illustration or decoration in a manuscript. Illuminated manuscripts played a major role in the development of art, partly because of the manuscript's portability in carrying artistic developments from one region to another.