The year is 131 AC. The Kingdoms were irrevocably split after the Targaryen Civil War, loyalties were divided amongst the various Targaryens. However, the civil war left all Targaryens dead except for four.

The Kingdoms splintered into seven distinct Kingdoms. The Targaryens, led by Vhinrea Targaryen would manage to keep the Crownlands and related holdings under their rule. Aeganys, as well as two other siblings were all that was left, they truly were the last Dragons. They kept Kings Landing as well their ancestral home of Westeros, Dragonstone, using Kings Landing as their seat of power. Their King sat at Kings Landing and Prince Aeganys sat at Dragonstone.

The rest of the Kingdoms after a period of turmoil united under the Dragon King, with the North and Stormlands remaining separate. Will the Kingdoms remain united or will a wedge be driven once again to cause them to separate? That is your choice.