A bombardment is an attack by artillery fire directed against fortifications, troops or towns and buildings. In its strict sense the term is only applied to the bombardment of defenceless or undefended objects, houses, public buildings, etc., by an assailant with the object of disheartening his opponent, and specially to force the civil population and authorities of a besieged place to persuade their military commander to capitulate before the actual defences of the place have been reduced to impotence. The practice was especially common during the 19th century; during the 20th century the tactic was largely superseded by the use of aircraft and missiles in various ways, under the general term "bombing".