Roman Cumbria to Wallsend on the Tyne estuary, with additional military installations running down the Cumbrian coast from Bowness to Risehow, south of Maryport, in an integrated fashion (and with forts at Burrow Walls and Moresby that were perhaps not part of the system). Historians believe that the Turf Wall from the River Irthing to Bowness-on Solway was rebuilt in stone in two stages. The most easterly five miles were rebuilt at the time of Hadrian, with the remainder being rebuilt after 150 AD. However, this is open to dispute: it is uncertain whether the building works in the second half of
Hadrian Arrian kept Hadrian well-informed on matters related to the Black Sea and the Caucasus. Between 131 and 132 he sent Hadrian a lengthy letter ("Periplus of the Euxine") on a maritime trip around the Black Sea, intended to offer relevant information in case a Roman intervention was needed. Hadrian also developed permanent fortifications and military posts along the empire's borders ("limites", sl. "limes") to support his policy of stability, peace and preparedness. This helped keep the military usefully occupied in times of peace; his Wall across Britania was built by ordinary troops. A series of mostly wooden fortifications, forts, outposts