In seeking to explain 13th-century pattern, two observations may be pertinent. Firstly, the Umfravilles did not attempt to administer the entire liberty from Harbottle alone, in the 13th century and thereafter. A subsidiary manorial centre, with a capital messuage (probably a two-storey hall-house typical of the region), was retained in Redesdale, overseeing the Umfraville holdings in that valley. However this was located not at Elsdon, but at Otterburn to the west, in the main valley.
Secondly, there is evidence to suggest the Umfravilles were attracted by the greater fertility of Coquetdale from the beginning of their tenure. They appear to have held the ten townships in Coquetdale and the Breamish valley from the reign of Henry I. Indeed the evidence is clearer than that for the Liberty itself. In the feudal inquest held by Henry II in 1166, Odinel de Umfraville made no return for his holdings, but William de Vesci, baron of Alnwick, recorded that Odinel held the ten townships from him for service of two knights fees. Moreover de Vesci declared the fees belonged to the older class of feoffment, those held before the death of Henry I in 1135 (Liber Niger Scaccarii, 329-39; cf. Hedley 1968, 21, 209; 1970, 90, 272).
This is confirmed by a law suit between Richard de Umfraville and Eustace de Vesci in 1207 over the wardship of the heir of Henry Bataille, who had held Fawdon and a part (moiety) of Netherton of Umfravilles for one knight's fee (Curia Regis R., 9 John, 58-60; Northumb Pleas, 30-1, no. 1030). Richard stated that Henry's grandfather, Gilbert Bataille, had first been enfeoffed by his great-grandfather Robert-cum-barba.
As Eustace de Vesci did not dispute that the Umfravilles were the first to enfeof Henry's ancestors and as the four-generation Bataille pedigree is clear, this puts both the Batailles' tenure of Fawdon and Netherton and by implication the Umfravilles' acquisition of the ten townships, through subinfeudation, securely back into the earlier 12th century. Furthermore, Walter Bataille, Henry's father, was recorded in 1166 as holding one of the Alnwick barony's older, pre-1135 fees (Preston and Brunton) directly of the de Vescis, but, if the statements in 1207 are to be believed, his lineage must have been enfeoffed of this holding after they had received Fawdon and the Netherton moiety from the Umfravilles. This would suggest that the granting of the block of ten townships to Robert de Umfraville was amongst the earliest acts of subinfeudation in the barony of Alnwick.
Furthermore, Holystone Priory must also have been established before 1153, as it figures in a summary of one of the lost charters of David I (RRS i, 111, 171 no. 93). Since the nunnery, which was situated in the liberty only a couple of miles downstream from Harbottle, was presumably founded by the Umfravilles on land they must have granted for the purpose, it provides a further indication of the attention the lineage was focussing on Coquetdale in the first half of the 12th century.
Given these factors two hypotheses can be advanced to explain the demise of Elsdon Castle. It is possible that the size of the Umfraville lordship, including the adjoining Coquetdale and Breamish valley townships in the barony of Alnwick, rapidly led to the realisation that it was inconvenient to administer the liberty and its appendages from a single centre. Consequently Elsdon was replaced by two manorial sites, each more centrally located in its respective valley, Harbottle in upper Coquetdale and Otterburn in Redesdale.
Alternatively it is conceivable that there were intitially two timber and earthwork castles, one to protect each valley. In this case Elsdon was abandoned, perhaps in the late 12th-early 13th century under Richard de Umfraville, because the liberty did not provide sufficient resources to support the reconstruction in stone and maintenance of two castles. This process of rationalisation in the face of the mounting costs of modernising castles in stone forms part of a common pattern, with many Norman earth and timber castles being abandoned with little or no documentary record.
It is noteworthy that Richard undertook major construction work at Harbottle c. 1220. In either case, it is likely that the Umfravilles were influenced by the greater fertility of the more northerly valley, in making Harbottle the principal focus of their liberty, in the same way that Coquetdale's upland pastures attracted greater interest from the monastic houses than did those of Redesdale. Thus, although reasons of state may not have been irrelevant in the final choice of the seat of the lordship and the construction of the castle at Harbottle, one may suspect that a decisive factor was the administrative and economic requirements of the Umfraville barons, themselves.