Another possibility is that Somairle was attempting to secure a swathe of territory that had only recently been secured by the Scottish Crown. Although there is no record of Somairle before 1153, his family was evidently involved in an earlier insurrection by Máel Coluim against David that ended with Máel Coluim's capture and imprisonment in 1134. An aftereffect of this failed insurgency may be perceptible in a Scottish royal charter issued at Cadzow in about 1136. This source records the Scottish Crown's claim to "cáin" in Carrick, Kyle, Cunningham, and Strathgryfe. Historically, this region appears to have once formed part of the territory dominated by the Gall Gaidheil, a people of mixed Scandinavian and Gaelic ethnicity. One possibility is that these lands had formerly comprised part of a Gall Gaidheil realm before the Scottish Crown overcame Máel Coluim and his supporters. The Cadzow charter is one of several that mark the earliest record of Fergus, Lord of Galloway, a Scandinavian-Gaelic magnate who held lands in Carrick. Fergus' attestation could indicate that, whilst Somairle's family may have suffered marginalisation as a result of Máel Coluim's defeat and David's consolidation of the region, Fergus and his family could have conversely profited at this time as supporters of David's cause. The record of Fergus amongst the Scottish elite at Cadzow is certainly evidence of the increasing reach of David's royal authority in the 1130s.