In summary, the tradition of painting was primarily preserved by monks in monasteries who churned out the illuminated manuscripts. (Come to think of it -- what a great comparison with this age! Just as the monks somewhat preserved the craft of painting through the Dark Ages by illustrating books, so many of the American illustrators such as Pyle, Parrish, Rockwell, etc. helped preserve the craft of painting during our Modern age.) This practice was particularly developed and kept alive in the northern countries, such as France and the Netherlands. When panel painting finally emerged with the likes of Jan van Eyck and Rogier van der Weyden, they were so adept at painting such amazing detail down to every leaf and flower because of their heritage of miniature painting. Conversely, the Italians emerged more out of a tradition of fresco painting, so they were not as interested in detail because of the limitations of the fresco technique.
Since the Byzantine empire was dominant throughout the dark ages, their painting tradition was very stylized and spiritual in nature and was seen primarily in icons and frescoes. Italy had tighter links to this culture during the dark ages than did the northern countries of Europe.
The arts of stained glass, metalworking, architecture and sculpture were the dominant mediums during this period, rather than painting, per se.
