Historical and archaeological evidence strongly supports the premise that ancient cities and settlements utilized walls primarily for military defense and protection.
The claim is a specific, empirically verifiable historical statement about the function of walls in ancient cities. Multiple retrieved archaeological and historical papers (such as [2], [7], [9], and [11]) explicitly discuss ancient fortifications, defensive walls, and fort-type settlements built for protection and military defense. There are no papers contradicting this well-established historical fact.