Mosque (Arab, mesjid, "place of prayer"), a Mohammedan temple or house of worship. The first mosque was erected by Mohammed at Medina, part of the work being done by his own hands. The site was a graveyard shaded by date trees, which was selected by the prophet because his camel knelt opposite to it on his public entry into the city. The edifice was square and capacious, the walls of earth and brick, and the roof supported by the trunks of palm trees and thatched with palm leaves. It had three doors. A part of the building was assigned as a habitation to the poor among the faithful who had no other homes. In this mosque Mohammed was buried; and though the original edifice was long ago replaced by a larger structure, the temple still bears the name of mesjid en-nebi, "the mosque of the prophet," and has ever since served as a model for the construction of Mohammedan places of worship. Everywhere the mosque is substantially the same in plan, though differing in detail in some countries, as modified by national taste.

What in Arabia was simple and elegant became highly ornate in Spain, florid in Turkey, and effeminate in India. In the reign of the caliph Walid I., toward the end of the 1st century of the Hegira, the cupola and the minaret were added to the mosque, and the Saracenic style of architecture was introduced throughout the Moslem world. The mosque of the prophet at Medina, the great mosque at Mecca, and the mosque of Omar at Jerusalem, are considered peculiarly holy, and are among the finest extant specimens of Moslem architecture. Cairo has about 400 mosques, the chief of which, that of Sultan Hassan, is a majestic edifice in the purest style. The jumma musjid or great mosque at Delhi, built by Shah Jehan in 1631-'7, is generally considered the noblest building ever erected for Mohammedan worship. The principal mosque of Constantinople was originally the Christian church of St. Sophia. The mosque of Solyman the Magnificent, begun in 1550 and finished in 1555, has six minarets. Attached to this mosque, as to almost all others, are various endowments for institutions of education, piety, and benevolence.

It has an annual revenue of 300,000 piasters.