User blog comment:M Bierhoff/Why is Avagraine in leauge with Morgana?/@comment-4623180-20111203090846

Agravaine wants anyone on the throne but Arthur- he blames Arthur for Igraine's death. They, in a real world point of view, would not have considered betrayal yet, as they're too busy deperately finding ways to get Arthur off the throne (or dead, for that matter).