Romanian church art of the fourteenth and fifteenth centuries is recognized as some of the finest and most unusual of the later period of Byzantine art. It differs somewhat in style from other examples of Byzantine art of that period by reflecting the influence of folk art. Some of the finest examples are found at the Moldavian monasteries of Putna, Sucevita, and Voronet. They are unusual in that they were painted on the outside walls in order to educate the peasants in church history and in elements of their faith. The quality and imaginativeness of these frescoes has been termed one of the great contributions to European religious art. Their freshness after more than 400 years of exposure to the elements is remarkable. In addition to paintings, religious art of the medieval period also included various objects, such as vestments, furniture, and vessels worked in wood, gold, or silver and richly decorated. Collections of these objects are preserved at the monasteries, the largest exhibits being at Sucevita and Putna. During the seventeenth century a change in style took place in painting and other decorative arts, although the subject matter remained religious. Russian artists who had come to Moldavia and Walachia introduced the small, detailed painting of Russian iconography, which became evident in the murals and other painting of Romanian artists. At the same time, the simple, folk art decorative forms were replaced by a more elaborate style showing both Baroque and Oriental influences. A distinct Walachian style developed, and schools emerged in Bucharest and other cities. The most notable achievements of the Walachian school are the interior frescoes of the Hurez Monastery. A secular trend was introduced into art in the eighteenth century with a greater involvement of merchants, craftsmen, and landowners as patrons. Not until the nineteenth century, however, did a completely secular art come into being, mostly through foreign influences. The earliest secular artists reflect in their styles the training they had received as religious artists.