User blog comment:Knightofthecart/Uther, the once and future king, part I/@comment-5102537-20130101112329/@comment-5674726-20130212000552

The Great Purge can never be justified, yet he did it for good reasons and it was unfortunately the mass murder of those who had/practised magic that brought peace to the land.

I'd say that, had Uther not sought/accepted Nimueh's help to use magic to bring a son into the world, he could have balanced stopping those who used magic to harm others without targeting those who had magic but didn't use it to cause harm. His grief over Ygraine's death led him to view all magic as evil, even when it seemed like it was going to be helpful at first.

The sad thing is that his decision to use magic to have a son was probably motivated by his love for his wife; he needed an heir for the future stability of his kingdom and, if Ygraine was barren, his duty to his kingdom would require him to end their marriage and find a new wife who could give him children. Magic gave him what seemed like a solution to that dilemma but the power of life and death isn't something to be trifled with, and Uther realised that to his cost when it was too late to turn back.