investigated several times by archaeologists going back to 1866. It was probably built by the Roman governor Gnaeus Julius Agricola in AD 79-80, during his campaign to conquer the north of Britain. (Agricola was the father-in-law of the historian Tacitus, who wrote a short book about him.) The fort measured about 330 by 360 feet (100x110 m), and there was a settlement or vicus outside the walls; excavations there found evidence of wattle and daub buildings. The place was occupied well after the last Roman troops were withdrawn from Britain in 410 AD, perhaps as late as 500. The photograph shows stones from the fort that were built into the parish church of the nearby town of Church Brough.
Brough, guarded by six knights, put up a strong resistance, but William took the outer defences and then besieged the keep, threatening to execute the garrison if the castle was not surrendered. The keep was set on fire, forcing the surrender of the garrison, including one knight who, according to the chronicler Jordan Fantosme, fought on first with spears and then wooden stakes, until finally overwhelmed. William then destroyed the remaining defences of the castle using Flemish mercenary troops.However Henry put down his son's rebellion, after which he sent Ranulf de Glanville, Chief Justiciar of England, into the north with a large force, and William withdrew. The Scots tried again the next year, but Glanville again came north, this time attacking William's forces near Alnwick Castle and routing them. That war pretty much sealed English control of everything south of Hadrian's Wall.