When selecting a predefined Souvereign and not choosing his own kingdom, you might meet yourself within the game.
E.g, i choose Lady Procipinee and Tarth as Kingdom, while Pariden was an enemy. As a result i met myself as shown below.

A solution would be to add a sixth Souvereign to Kingdoms and Empires, which is used when the appropiate Souvereign was choosen by the player. Or simply switch in the original souvereign of the players empire.