Rǫgnvaldr Óláfsson (fl. 1164)
In 1164 , when Somairle was killed in an invasion of Scotland , and while Guðrøðr was away in exile overseas , Rǫgnvaldr briefly seized the kingship for himself , before being overcome by Guðrøðr , who had him blinded and mutilated . 
<triplet> an invasion of Scotland <subj> 1164 <obj> point in time