Elsdon : Strategic Considerations
However, the circumstances whereby the seat of the lordship came to situated at Harbottle, involving a presumed shift from Elsdon, which paradoxically resulted in the 'liberty of Redesdale' being administered from a castle in Coquetdale, remain much less clear.
It must be admitted that, whether examined from the standpoint of strategic requirements of border defence, or the administrative and policing considerations of the Umfraville barons, Elsdon does not at first sight appear badly positioned. Its location beside the Elsdon burn, a tributary of the Rede, meant the castle lay on the best natural route between Redesdale and Coquetdale, which follows the Elsdon and Grasslees burns. It was thus an excellent centre from which to intervene in both dales.
In addition it straddled the main road leading from Newcastle to Redesdale which wound through Belsay, Cambo and Steng Cross (the predecessor of the present A696, which was not established until the turnpike era). Beyond Elsdon the traveller could carry on down the Elsdon Burn into the main valley of the Rede or climb the trackway which ran along the high moorland watershed between the Redesdale and Coquetdale to join the course of Dere Street - or Gamelspeth as it was known at this point - as the latter approached the border crossing. This moorland trackway was to become one of the principal drove roads from Scotland to the markets of England, the Great Drove (or Drift) Road, but may have an ancestry, as a ridgeway, running far back into prehistory (Charlton & Day 1976, 229; cf. Rushworth 1996, 19). South of Elsdon this routeway aimed directly for Stagshaw Bank and Corbridge.
The castle was thus situated at a major communications hub. Although it lay at the eastern end of the liberty this was less of a disadvantage than it might first appear. The western, uppermost stretches of both valleys being devoid of permanent settlement and given over to seasonal grazing and the lord's hunting pursuits. This was particularly marked in Redesdale where the hospital at Elishaw marked the limit of permanent occupation.
For its part, Harbottle Castle occupies a good defensive position with extensive views both up and down the valley and lies at the point where the Coquet begins to open out. The line of Clennell Street can be kept under observation from the site and, moreover, The Street, which follows the course of the Coquet down from the border, joins Clennell Street at Alwinton, a short distance above Harbottle, so that traffic along both routes can be monitored from the castle. The Gamelspeth (Dere Street) border crossing can also be reached by following the Coquet right to its source beside Chew Green. It is thus a site of some strategic importance (Bowden 1990; Crow 2004; Hunter Blair 1944, 136; Rushworth & Carlton 1998), and is also situated closer to the border than is Elsdon Mote Hills, which may have been significant.
Nevertheless, however well its situation in Coquetdale enabled it to dominate and protect that valley, the castle appears ill-placed to perform those roles in Redesdale proper. Admittedly Harbottle is also situated relatively close to the point, at Holystone, where the Roman road between Dere Street and the Devil's Causeway crosses the Coquet. This road, leading to High Rochester, may still have survived in some form.
It would have have provided a link with upper Redesdale, but it is unclear how much use it saw in the medieval period. Even so Harbottle Castle could not have monitored and policed traffic along Dere Street and the Redesdale valley route, which led up to the border at Redeswire (close to modern Carter Bar). Hence the castle's position straddling certain cross-border communications routes cannot fully explain why the seat of the lordship was shifted to Harbottle. Clennell Street, called the 'great road of Ernespeth' in the charters of Newminster abbey (hence modern Yarnspeth), and The Street may have been important, but not demonstrably more so than Dere Street (Gamelspeth) and the Redesdale valley route, which retained their significance during war and peacetime throughout the medieval period.
The Scottish army of Earl Douglas was aiming for one of these routes in 1388, before they were intercepted by Hotspur's forces at Otterburn, and Sir Robert dede Umfraville routed another Scottish raiding force at Redeswire in 1400. In the Laws of the Marches, formalised in 1249, but probably of much greater antiquity, the Gamelspeth border crossing was the designated place where individuals from Coquetdale and Redesdale would make formal rebuttal of charges against them in cases of legal disputes with Scots (Leges Marchiarum; cf. Barrow 1966, 39-40), presumably because this crossing point could be reached conveniently by the inhabitants of both valleys.