Actually, this just came to my mind...

What if Shiva (the real one) was Haldrath's sister, King Thordan I's daughter? She fell in love with Nidhogg and brought the Spoken and dragons closer together, but Haldrath grew jealous of her happiness or didn't trust the dragons. This drove a wedge between Dravania and Ishgard until they teetered on war until Shiva somehow sacrificed herself to try and bring peace. At some manner of peace summit brokered with Shiva's life (possibly the Akh Afah Ampitheatre or the area we've been shown to meet Hraesvelgr at), Haldrath betrayed Thordan, killed him, and gouged out Nidhogg's eye. Then everything was covered up, the Holy See formed, and the Dragonsong War begun.

Thoughts?