fortlet

A fortlet is a small fortified site used as an outpost or minor strongpoint within a larger defensive network. The term is employed in archaeology and military history to describe a fortification that is smaller than a main fortress or garrison town and intended to support frontier or coastal defense.

Typical fortlet features vary by period and region, but most share a compact, defensible layout. Common elements include earthworks or stone walls, a surrounding ditch or rampart, and a limited number of gateways. The internal arrangement often comprises a handful of buildings such as guardrooms, storehouses, barracks, and sometimes a command or administration space. Some fortlets relied on timber defenses rather than stone, while others used more substantial walls with posts or small buildings inside.

Functions of fortlets include guarding routes and crossings, protecting coastlines or river mouths, and serving as waypoints along a frontier. They could provide early warning, secure supply lines, and project military presence over a defined area. Because of their small size, fortlets typically housed a small garrison and depended on nearby larger forts or settlements for support.

Fortlets are documented in diverse historical contexts, including ancient, medieval, and early modern periods. They are identified by archaeologists and historians based on their size, defensive features, and spatial relationship to other fortifications. The variability of construction and use reflects differences in technology, terrain, and strategic needs across regions and eras.