History of the Sword Coast

The Demon Lord Yeenoghu baits the Zarielite Crusaders into attacking him near the village of Idyllglen. During the battle, Yeenoghu grabbed General Yael and fled through a portal to Avernus. The crusaders followed after, nearly destroying the demon lord's army, before an army of devils arrived.   Jander Sunstar fled the battle with a large chunk of the army and the portal closed behind them. In the resulting three-way battle, the Hellriders were destroyed, though not before Zariel slew a member of the Dark Eight. Feeling herself slipping, Zariel ordered Yael and Lulu to flee with her sword.   Afterwards, Zariel was given the offer to be reborn as an archdevil by Asmodeus, which she accepted.

The Reckoning was a tripartite conspiracy masterminded by Glasya to convince half of the lords of the Nine Hells that the other half were planning a rebellion and vice versa.   Zariel, who was secretly working with Glasya, spent nearly the entire war besieging Dis until she was betrayed by Tiamat, who attacked her forces from behind, breaking the siege.   Following the Reckoning, the balance of power shifted in nearly all of the Nine Hells, and Zariel was imprisoned by Tiamat.

The unexpected opening of a rift in Avernus allowed an army of baatorians, the original Avernian inhabitants thought extinct, to pour out, throwing the Blood War into disarray.   Bel, the Archduke of Avernus, was caught flat-footed and his armies were forced into a rout.   Glasya, seeing an opprotunity, arranged for Zariel's release from Tiamat's prison. Newly freed, Zariel rallied the forces of Hell and drove the baatorians back, turning the tide of the war during the Battle of Lost Memories and finishing the baatorians off during the Rift Siege.   For her success, Zariel was made Archduke of Avernus and Bel was demoted to the Dark Eight.

The final battle of the Great Dragon War saw a massive success for the allied forces. Inside the Well of Dragons, Tiamat's resurrection was prevented, thanks to interference from the Breadwinners.