[alcuin]

King Sigurd is a bad example for two reasons. One being that you are implicitly conflating Scandinavians with Vikings, when the latter were a subset of pirates largely disjoint from the aristocracy to which Sigurd belonged. The second is that Sigurd and his men did in fact attack and plunder fellow Christians on their way to Jerusalem when they stopped in Galicia in the winter of 1108. You can read about it in the Historia Compostelana.