The king was desirous that as many of the materials as possible for the structure should be collected from his own dominions. These were so vast, and so various in their productions, that they furnished nearly every article required for the construction of the edifice, as well as for its interior decoration. The grey stone, of which its walls were formed, was drawn from a neighbouring quarry. It was called _berroquena_,--a stone bearing a resemblance to granite, though not so hard. The blocks hewn from the quarries, and dressed there, were of such magnitude as sometimes to require forty or fifty yoke of oxen to drag them. The jasper came from the neighbourhood of Burgo de Osma. The more delicate marbles, of a great variety of colours, were furnished by the mountain-ranges in the south of the Peninsula. The costly and elegant fabrics were many of them supplied by native artisans. Such were the damasks and velvets of Granada. Other cities, as Madrid, Toledo, and Saragossa, showed the proficiency of native art in curious manufactures of bronze and iron, and occasionally of the more precious metals. Yet Philip was largely indebted to his foreign possessions, especially those in Italy and the Low Countries, for the embellishment of the interior of the edifice, which, in its sumptuous style of decoration, presented a contrast to the stern simplicity of its exterior. Milan, so renowned at that period for its fine workmanship in steel, gold, and precious stones, contributed many exquisite specimens of art. The walls were clothed with gorgeous tapestries from the Flemish looms. Spanish convents vied with each other in furnishing embroideries for the altars. Even the rude colonies in the New World had their part in the great work, and the American forests supplied their cedar and ebony and richly-tinted woods, which displayed all their magical brilliancy of colour under the hands of the Castilian workman.[461] Though desirous, as far as possible, to employ the products of his own dominions, and to encourage native art, in one particular he resorted almost exclusively to foreigners. The oil-paintings and frescoes which profusely decorated the walls and ceilings of the Escorial were executed by artists drawn chiefly from Italy, whose schools of design were still in their glory. But of all living painters, Titian was the one whom Philip, like his father, most delighted to honour. To the king's generous patronage the world is indebted for some of that great master's noblest productions, which found a fitting place on the walls of the Escorial.