must have occurred earlier in Arabia and in Persia, when the war-lords of Islam had few building craftsmen except those they took prisoner or imported from other countries. The Buddhist images were torn from their niches and broken up or melted; the former temple or monastery, if not utterly destroyed, was used as a place of Muhammadan worship, and the empty niches (mihrābs) with their arches—lancetted, trefoiled, or sometimes of the earlier Hīnayāna trefoiled form—remained in the walls. The principal one in the western wall of the converted mosque pointed the direction to which the faithful must turn when saying their prayers, and was called the "Kiblah"[1]; so the arched niche was retained in every newly-built mosque and became a symbol of the faith. In private houses the numerous small niches which formerly had served as shrines for the saints, or household gods, of Mahāyāna Buddhism, were also retained: they were useful as cupboards or receptacles for the hookah, rose-water vessel, lamp, or other article of domestic use. The niche with its changed contents became as common a motif in the Muhammadan art of Arabia, Persia, and India, as it had been when it was the shrine of a Buddhist saint.
It followed almost inevitably that the pointed or horse-shoe arch was also used structurally for window and door openings instead of the semicircular Roman arch or the beam of the temple portico. The Persian builders quickly perceived the wonderful colour effects produced by their enamelled terra-cotta—an art which they had inherited from Babylon and Nineveh—when placed upon the curved surfaces of the niche, and the convenience of placing a doorway or window under the shelter of its semi-dome instead of building
- ↑ From Arabic Qabala, to be opposite.
