Originally Posted by NewChief
I do know that Jorah told Viserys in that he hates Robert because Robert persecuted/prosecuted him for killing some poachers on his lands. Viserys responded with, "I can assure you that such things won't happen under my reign." So, he's basically in exile and wanting to help the Targaryens because he hates Robert.
I think it was Ned Stark rather than Robert.