If Suibne nevertheless ruled in Galloway, the notices of his death could be the first known instances of the term "Gall Gaidheil" in associated with the region. It would also mean that he was a precursor to the similarly-styled Gallovidian rulers. A more-contemporary figure, Echmarcach mac Ragnaill, King of Dublin and the Isles, may well have ruled in Galloway as well, if the style ""rex Innarenn"", accorded to him by Marianus Scottus, means "King of the Rhinns", as opposed to the possible "King of the Isles". In about 1031, Echmarcach was one of several northern kings who convened with, and possibly submitted to, Knútr Sveinnsson, ruler of the Anglo-Scandinavian Empire comprising the kingdoms of Denmark, England, and Norway. If Suibne and Echmarcach were indeed associated with Galloway, Echmarcach's dealings with the English king—only a few years before the Suibne's death—could suggest that Echmarcach and Suibne were rivals within the region.