vallum

Vallum is a Latin term meaning rampart, mound, or embankment. In Roman military architecture, vallum denotes the earthwork that formed a defensive perimeter around a fort, marching camp, or frontier installation. The feature is typically referenced alongside the fossa (ditch) and, when present, a timber palisade or parapet on top, creating a protective barrier around the interior.

Construction and variants: The usual configuration involved an earthen bank (agger) with a ditch in front of it, sometimes accompanied by a timber stockade on the crest. The precise arrangement varied by region, period, and fort type; in some sites a stone revetment or additional wooden structures were added to strengthen the defense. Vallum features could enclose entire forts or smaller camps and often defined the edge of the inhabited or garrisoned space.

Function and usage: The vallum served to impede attackers, channel approaches, and provide a defensible platform for guards and troops. It worked in concert with gates, curtain walls, and towers to control access and observation. While most closely associated with Roman fortifications, the concept of an earth-and-wood rampart is a common defensive motif across various Roman frontier installations and later settlements.

Etymology and modern usage: The word derives from Latin vallum, used across the Roman world to describe earthworks and ramparts. In contemporary archaeology and historical writing, vallum remains a technical term for the earthen boundary features around forts, marching camps, or fortified enclosures, and is used to identify and interpret defensive landscapes in Roman sites.