The four Jezreel Valley Regional Project (JVRP) seasons of excavation at Legio (2013, 2015, 2017, 2019) focused on the principia (headquarters building) of the Roman Sixth Ferrata Legion’s base, identified in the middle of el-Manakh hill (Fig. 1), approximately halfway between Tel Megiddo and the third-century CE Christian Prayer Hall of  Kefar ‘Othnay (Tepper 2006; Tepper and Di Segni 2006). The JVRP excavations followed extensive surveys conducted at the site between 1998 and 2002, which pointed to the possible location of the base and the Roman-Byzantine city of Maximianopolis (Tepper 2002; 2003; 2007; 2013). These explorations retrieved finds ascribed to the Roman legion, and documented the remains of Roman-period aqueducts, imperial roads, an amphitheater and the legionary necropolis (Fig. 1). In the first JVRP excavation season (2013), the site was tested through a longitudinal section that cut through the remains of the northern fortification system and barracks (Area A; Fig. 2), confirming the location of the legionary base hypothesized by Tepper (Tepper 2003; Tepper, David and Adams 2016). The following two seasons focused on excavating the central part of the legionary base (Areas B, C; Fig. 2)—the principia and the main street of the base, the via principalis—and on remote sensing studies of the site with Ground Penetrating Radar, laser imaging, detection and ranging (LiDAR) and aerial photogrammetry (Fig. 2; Adams et al. 2019). While the excavations focused on the activity of the Roman Sixth Legion at the site, small finds and in situ remains of the Intermediate Bronze Age and of the period of occupation by the British Army were found.
In the 2019 season, work continued in Areas B and C, representing two distinct parts of the principia compound. Its findings further elucidated the layout of this compound, now dated with more certainty to the second–fourth centuries CE.
Area B: The Basilical Hall of the Principia (Fig. 3). The work focused primarily on the sacellum, the cultic chamber dedicated to the imperial cult and the housing of the legionary standards. The general plan of the room was traced, revealing the remains of stylobates and of the main altar and evidence for a remodeling of the room in a late phase of its use. The finds included fragments of bronze and stone statuary, as well as architectural elements.
Area C: The Gate and Courtyard of the Principia (Fig. 4). The excavation at the main gate leading into the principia compound from via principalis was continued. The eastern facade of the principia was traced southward, identifying the southeastern corner of the building, the interior portico, storage chambers (armamentaria) and parts of a courtyard and its drainage system.
The main research goals of the project were advanced by further elucidating the principia layout, refining our chronological understanding of the Roman army occupation at the site, and providing new data on day-to-day activities carried out at the base.