There is no difficulty in affirming that this form of earthenware was made at Toledo, for Marineo Siculo, in his interesting volume treating of "De las Cosas Memorables de España," Alcala, 1539, says, "much coarse green and white pottery is made at Toledo." [Illustration: BRIM OF WELL FROM TOLEDO. SOUTH KENSINGTON MUSEUM.] The manufacture of tiles, as was the case with so many other industries in Spain, was imported by the Arabs. In the Middle Ages it attained great importance, and has never ceased in Spain up to the present day. The earliest tiles (_azulejos_) made in Spain are composed of small pieces let into the wall, forming geometrical patterns. The proceeding is similar to that employed by the workers of Byzantine mosaic,--tile decoration undoubtedly took the place of this mosaic work in Moorish buildings. It is difficult to fix the precise period when they were first made, but it must have been posterior to the 10th century, when Moorish architecture underwent a radical change in its system of decoration. The oldest tiles which exist in Spain are at the Palace of the Alhambra, Granada. They belong to the 14th century. The great variety of their design may be seen in Owen Jones' "Plans and elevations of the Alhambra," London, fol. 1842, and the fine work published by the Spanish government, "Monumentos Arquitectonicos." We can judge of the style adopted by two interesting fragments, both of which came from the Alhambra, No. 1104-'53, No. 324-'64, South Kensington Museum. The earliest mention which I have found of this manufacture occurs in a letter from Doña Juana de Mendoza, the wife of the Almirante de Castilla, which is addressed to the lady abbess of the nunnery of Santo Domingo at Toledo. She begs that a large number of "azulejos" of different colours, black, white, yellow, and green should be sent to her. She alludes, in the same letter, to painted tiles, and says she was expecting a master potter from Seville to place these tiles in their proper places. This shows us that it was only in the province of Andalusia that the art was known of cutting these tiles into geometrical sections and mosaic patterns. This letter is not dated, but it is bound up with other documents of 1422, and evidence exists to prove that both the Almirante and his wife were dead in 1431. The locality for which the tiles were required was probably Palencia; the convent of Santa Clara was built by them at that time, and they both were buried there. It was extremely difficult to cut and join together these tiles; the workmen who did so had to pass through a regular examination in compliance with the municipal ordinances drawn up in the 15th century; without this requisite they were not allowed to exercise their trade.