El-Lejjun, also known as Betthorus, is a well-preserved Roman military fortress located in Jordan’s Karak Governorate, near the edge of the eastern desert. Established in the late 3rd or early 4th century CE, it was part of the Limes Arabicus, a defensive frontier system protecting the eastern boundaries of the Roman Empire. The fortress was home to the Legio IV Martia, a Roman legion tasked with guarding trade routes and repelling raids from desert tribes. The fort’s rectangular layout, strong stone walls, corner towers, and gatehouses reflect typical Roman military engineering designed for both defence and administrative control.

El-Lejjun also played a role during the Byzantine period, with evidence of continued occupation and modification. Remnants of churches, barracks, and a praetorium have been discovered, illustrating the site’s evolution from a purely military outpost to a broader settlement. The presence of water cisterns and aqueducts demonstrates the strategic importance of sustainable infrastructure in the arid environment. Today, El-Lejjun stands as a significant archaeological site that offers insight into Roman and Byzantine frontier life in the region, and it serves as a key piece of Jordan’s historical landscape.