In the centuries of the Middle Ages, the Church was the great power, not only in religious matters, but even in the decorative arts. Mosaics, painting, carving, embroidery, colored glass were all of use in beautifying the churches; and this fact was a great encouragement to their production. Mosaics were made by the Greeks in very early times, and from them the Italians learned the art. The "tessellated floors" of which we read in descriptions of churches and palaces were one variety of mosaic. The kind most used in Italy was made by taking slabs of white marble as a foundation. Grooves were cut into it, which were then filled with little cubes, or "tessellæ," of colored stone to form patterns. Of course in the Byzantine mosaic work one would expect much brilliancy and color. This was obtained by using bits of glass instead of stone. A sheet of gold leaf was laid between two sheets of glass and burned in a kiln. It was then broken into bits, which served as a background for the figures or designs. These designs were made of differently colored glass or marble. The tiny pieces were firmly fixed in cement, and most elaborate pictures were the result. One of the most famous is called "Pliny's Doves." It represents four doves sitting on a metal basin, one of them stooping to drink. When altars and walls and pulpits gleamed and glittered with mosaic work in the dim light of some vast cathedral, the effect was far more rich than that produced by any other species of ornament.

Instead of covering church walls with mosaic, fresco was sometimes used, that is, painting in water color on damp plaster. This lasted well, because the colors sank into the plaster; but the drawing was stiff and the faces had little expression, until the coming of an artist named Cimabue, in the thirteenth century. The faces that he drew looked like those of real people with real thoughts and feelings. His draperies, too, were not prim and wooden, but hung as if they had been painted from real folds of cloth. It is said that when his famous "Madonna" was to be carried to the Church of Santa Maria Novella, the people formed in procession to do it honor, and shouted joyfully when the artist appeared among them. Cimabue one day noticed a shepherd boy drawing on a rock a picture of his sheep. It was so well done that the artist took the boy under his protection and taught him. This boy became the famous Giotto. The faces that he painted look as "real" as those of Cimabue; and he even painted portraits of living people and ventured to make them look like the people. It was Giotto who painted the portrait of Dante which has been handed down to us. The backgrounds, however, of Giotto's work, like those of other artists of the time, were not like nature. If there was a landscape, the trees were thin and rigid and not in the least like real, growing trees. Frequently the background was of gold. Indeed, to the artists of the time there could hardly be too much gold in a picture. To-day if an artist introduces a crown or a pair of gilded spurs, for instance, he tries to produce the effect of gold by the skillful use of lights and shadows; but the artist of mediæval times simply embossed real gold on the picture. This would hardly be called artistic, but it made a design brilliant and rich, a splendid piece of decoration.

Another famous painter was the monk Fra Angelico. He did not know that he was an artist, but in his leisure moments he covered some blank pages of a manuscript with such dainty little miniatures that his brother monks were delighted. "Paint a picture," they urged, and he painted. By and by the Pope heard what he was doing, and sent for him to paint one of the chapels of the Vatican. It was so well done that the Pope wished to make him an archbishop in reward; but the monk refused the honor. He felt that God had given him a gift which it would be wrong to neglect for the sake of a high position, and he went back to his little cell to paint. He painted many diptychs and triptychs, or two-fold and three-fold tablets. These were often used as ornaments for the altar. The triptych especially was quite elaborate. It was a wooden panel often carved quaintly in Gothic designs, and shut in by two little doors. On the outside of the doors the artist painted pictures, frequently the portraits of the donor and his wife. On the inside there were pictures of saints or scenes from the Bible. The background of the figures is usually gold, still bright and gleaming after all the hundreds of years. Hawthorne says that if Fra Angelico's imagination had not been pure and holy, he could never have painted such saints, and that he must have said a prayer between every two touches of his brush.

The painting that was done on manuscripts was called illuminating. At the beginning of the Middle Ages the parchment was sometimes dyed purple, and the whole book written in letters of gold or silver almost as regular as print. Of course such books as these were enormously expensive. In the thirteenth century, a finely written Bible was sold for enough to pay a workman's wages for twenty-six years. Of course not many books were as expensive as this, but they were all very costly. Most volumes were decorated, even those that cost no more than a house or two. The margin of the frontispiece was generally painted, and there were often borders to the pages and most elaborate initials, sometimes entwined with flowers and vines and sometimes showing pictures of saints or even of whole Bible scenes. No one thought of trying to find out how people dressed in Bible times, and therefore the illuminators simply copied the dress of their own day. Artistically, this was not very correct; but it is a great help in learning about the costumes of the Middle Ages. The reds and blues and greens in these illuminations are as fresh and bright as ever, and the gold looks as if it had been put on only an hour ago. Much expense went into the binding. The covers were sometimes of wood and sometimes of leather. They were ornamented with gold and silver filigree work at the corners, or with heavy knobs of the precious metals. Often they were set with jewels. Sometimes the covers were of ivory, most delicately carved. If a man was fortunate enough to own a book, he was exceedingly careful to whom he gave the privilege of opening its clasps. As to lending it, that was not done as a matter of friendship by any means. The borrower must give ample security that he would return it uninjured. Even kings were not excepted. When Louis XI, king of France, wished to borrow of the faculty of medicine of the university of Paris the works of a certain Arabian physician, he was not only obliged to give valuable security, but he had to obtain a wealthy endorser just as if he were an ordinary man, and not the ruler of the land.

As the style of church building changed, the fashion of decorating churches changed also. The Gothic churches had many windows and few flat surfaces, and so they afforded little space for painting on the walls. But the windows were fine and lofty; and here was the best opportunity in the world for colored glass. Throughout the Middle Ages, the common way of making these windows was to prepare glass of the various colors needed, and then cut it into the shape of the object. If a figure wore a red cloak, for instance, it was first sketched, then the red glass was cut into the shape of the cloak as it appeared in the picture, and this was fastened to the other pieces by a narrow strip of lead, so that the lead traced all the outlines of the picture. The shading and those parts of the design which were too small to be shown by separate bits of glass were painted with dark brown. The colors are sometimes brilliant and glowing, sometimes rich and dark.

Enamel was much used, with its soft gleam rather than with the flashing, glowing beauty of stained glass. To represent a figure in enamel work, the artist cut down into a plate of copper, leaving the outline of the figure of the full depth. Then into the shallow depressions of the figure he put a glassy substance in whatever color was needed and melted it in a furnace until it flowed and filled the whole depression. Then he polished the plate, and it was done. Later, artists used to make the whole figure in copper, finishing it with delicate lines of engraving, and using enamel for the background. Hanging lamps, altars, chalices, crosses, bells, and monstrances, and many articles of jewelry, such as clasps, chains, necklaces and bracelets were adorned with enamel.

A vast amount of sculpture was used in the churches. In the Gothic architecture, especially in France, statues were everywhere. Including bas reliefs and scenes portrayed on the windows, the cathedral at Chartres is said to contain ten thousand figures. Besides the statues which were a part of the church and were used expressly to adorn it, there were recumbent memorial statues for tombs, which were at first stiff and unreal, but which came to represent with considerable truth the persons in whose honor they were made. In some places it was the custom to model statues in wood or wax as true to the original as possible and lay them upon the biers of wealthy people at their funerals. Little statuettes were often made in wood or ivory for ornaments. Reliquaries were frequently made in the shape of some saint with a tiny tabernacle to hold a relic. The whole tusk of the elephant was sometimes used in a carving, and the carvers made their figures lean back in a peculiar fashion to accommodate the curve of the tusk. People were very fond of bas reliefs. The tympanum, that is, the space between the top of the door and the angle of the roof, was often carved in relief to represent a whole story. On the capitals, or heads of the columns, and on the friezes men and animals were sculptured. Diptychs and triptychs were made of ivory with minute carvings representing scenes in the life of Christ or of the Evangelists. This carving was sometimes picked out with color or with gilding.

In point of naturalness there was a vast difference between the Romanesque art and the Gothic. The Romanesque made a magnificent decoration; but it paid little attention to nature. The figures were wooden and unnatural, and the draperies stiff and rigid. Gothic art studied nature. The Gothic artists tried to make figures look like real persons, and to make the carved draperies hang as real draperies of cloth would hang. When they carved flowers and foliage, they studied those that were native to the place where the carving was to be and did their best to imitate them. In the Gothic cathedrals, this carving and painting was not wholly for beauty by any means. The work was done according to the orders of the clergy, and they never forgot that the church was the school of the common folk. That is why not only animals and plants, but scenes from the Bible and legends of saints were shown. There were carvings to represent the seasons, the arts and crafts, even stories introducing the virtues and vices in the form of persons. In the earlier times, in much of the Romanesque art, dragons and griffins and monsters of all sorts appeared; but now these were seen only as gargoyles, that is, at the end of spouts which carried away water from the roof gutters.