Chessenta

In 1372, Tiamat was slain on her home plane by Dorian Adricus and others.

She had previously subsumed Tchazzar, a risen mortal dragon who once took human form, led the nation of Chessenta to glory, only to die in a most heroic and ambiguous way, promising his some-day return. He figured this would create a cult of worshippers that would make him a god. He was right. But, being a dragon, he was well within Tiamat's orbit, and she wasn't about to let him have the tiniest slice of her power, so she bound him to service and subsumed his portfolio (small as it was).

The death of Tiamat freed Tchazzar, and likely allowed him to inherit some fraction of her divine power (though just how much is not known). Being a demigod, he was able to freely exist on Toril in corporeal form, once he managed to hitch a ride back to his home plane.

Thereafter, he worked for a time in shadow to prepare for his glorious return. In 1377, amidst the chaos of war between Chessenta, Unther, and Mulhorand, he publicly reappeared, quickly gaining a massive following. Before long, he was named Sceptenar of Chessenta, and understood to be a dictator in all but name. He swiftly wiped his hands of the war in the east and set about consolidating power.

In 1380, he led Chessenta to war with Chondath, easily overpowering the weak alliance of city-states, and claiming their lands as prize of conquest. He also bore children with Anastasia, Empress of Thay; though the two never formally married, they very publicly proclaimed their love, and it was understood that Chessenta was now allied with the resurgent Thayan Empire...a nightmare scenario for the rest of the Sea of Fallen Stars, to be sure.

Tchazzar's Parentage and Powers

Canon seems to waffle on this point, but the fanon is clear:

• Tchazzar was born in the Year of the Thirsty Sword, 900 DR.
• His father was an unknown red dragon. Tchazzar himself knows not of his father's identity.
• His mother was a sorceress, who never actually spoke her true name to him. She lived on a small island in the Bay of Chessenta. She well may be immortal, because she's still freaking alive.
• It was she who devised the plan for his glorious rise to power. She has always controlled him, manipulated him, used her affections to undermine his will.

Or at least that's what he told Ani.