A short time later, perhaps in about 1225 or 1226, the chronicle reveals that Rǫgnvaldr oversaw the marriage of a daughter of his to Alan's young illegitimate son, Thomas. Unfortunately for Rǫgnvaldr, this marital alliance appears to have cost him the kingship, since the chronicle records that the Manxmen had him removed from power and replaced with Óláfr.McDonald (2019) pp. 24–25, 46, 48, 62; Oram (2013); Oram (2011) pp. 189–190; McDonald (2007a) pp. 64–65 n. 87; McDonald (2007b) pp. 81, 155, 172; Brown, M (2004) p. 78; Oram (2000) p. 126; Duffy (1993) p. 105; Oram (1988) p. 137; Anderson (1922) pp. 459–460; Munch; Goss (1874a) pp. 88–91. The recorded resentment of the union could indicate that Alan's son was intended to eventually succeed Rǫgnvaldr,Oram (2013); McDonald (2007b) pp. 155, 157; McNamee (2005); Brown, M (2004) p. 78; Oram (2000) p. 126; Stringer (1998) p. 96; McDonald (1997) p. 92. who was perhaps about sixty years-old at the time, and whose grandchildren were presumably still very young. In fact, it is possible that, in light of Rǫgnvaldr's advanced age and his son's mutilation, a significant number of the Islesmen regarded Óláfr as the rightful heir. Such an observation could well account for the lack of enthusiasm that the Manxmen had for Alan and Rǫgnvaldr's campaign in the Hebrides.Oram (2000) p. 126. Since Thomas was likely little more than a teenager at the time, it may well have been obvious to contemporary observers that Alan was the one who would hold the real power in the kingdom.Oram (2000) pp. 126, 139 n. 107. From the perspective of the Scottish Crown, it is conceivable that Alan's ambitions in the Isles were encouraged by the prospect of Alan's son becoming a dependable client-king on Mann, and the potential to further extend and strengthen Scottish royal authority along the western seaboard, bringing stability to the war-torn region.Oram (2013); Oram (2011) p. 190; Oram (2004a); Oram (2000) p. 127; Stringer (1998) pp. 96–97. As for Alan—a man who faced the probability that Galloway would be partitioned between his legitimate daughters on his eventual death—the marital alliance may have been conducted as a means to ensure a power base for Thomas, whose illegitimacy threatened to exclude him from inheriting his father's domain under the feudal laws of the English and Scottish realms.Oram (2000) pp. 126–127; Stringer (1998) pp. 96–97.
