Several authorities who accepted the structure's interpretation as a Roman road attempted to make more precise estimates of the date of its construction by identifying periods of Roman military activity in the region since most Roman roads were of military construction. Historian Albert Norman, writing in 1960, states that the Wheeldale structure most probably dates from either the first or fourth-century AD but most sources appear to favour the first-century date: both historian Brian Hartley and Hayes & Rutter estimate around 80 AD; and Elgee estimates 86 AD. The earlier, first-century estimates assume that the road is Roman and that Roman road-building in the region occurred around the time that Gnaeus Julius Agricola was the Roman governor of Britain. Agricola made a concerted effort to expand and consolidate Roman control over lands of the Brigantes tribes in the North York Moors area in the 80s AD and is thought to have ordered the construction of nearby Lease Rigg fort. The fourth-century estimates, by contrast, assume that the tribes in the North York Moors area were either bypassed or subdued in the first century but that, being of little importance strategically, their lands were not subject to Roman occupation or construction until the fourth century. A second wave of Roman military activity appears to have occurred in the region during this later period in response to new military incursions and raiding by Saxons, Picti, Scoti and Attacotti. The east coast of the North York Moors area formed the northern flank of the Saxon Shore defences believed to have been constructed against this perceived threat.