BATTLEMENT (probably from a lost Fr. form bastillement, cf. mod. Fr. bastille, from Med. Lat. bastilia, towers, which is derived from Ital. bastire, to build, cf. Fr. bâtir; the English word was, however, early connected with "battle"), a term given to a parapet of a wall, in which portions have been cut out at intervals to allow the discharge of arrows or other missiles; these cut-out portions are known as "crenels"; the solid widths between the "crenels" are called "merlons." The earliest example in the palace at Medinet-Abu at Thebes in Egypt is of the inverted form, and is said to have been derived from Syrian fortresses. Through Assyria they formed the termination of all the walls surrounding the towns, as shown on bas reliefs from Nimrud and elsewhere. Traces of them have been found at Mycenae, and they are suggested on Greek vases. In the battlements of Pompeii, additional protection was given by small internal buttresses or spur walls against which the defender might place himself so as to be protected completely on one side. In the battlements of the middle ages the crenel was about one-third of the width of the merlon, and the latter was in addition pierced with a small slit. The same is also found in Italian battlements, where the merlon is of much greater height and is capped in a peculiar fashion. The battlements of the Mahommedans had a more decorative and varied character, and were retained from the 13th century onwards not so much for defensive purposes as for a crowning feature to their walls. They may be regarded therefore in the same light as the cresting found in the Spanish renaissance. The same retention of the battlement as a purely decorative feature is found throughout the Decorated and Perpendicular periods, and not only occurs on parapets but on the transoms of windows and on the tie-beams of roofs and on screens. A further decorative treatment was given in the elaborate panelling of the merlons and that portion of the parapet walls rising above the cornice, by the introduction of quatrefoils and other conventional forms filled with foliage and shields.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)