Military action
"Karrn was a great military leader, of that no one can doubt. It is with him that the Karnnathi identity as we know it today began to form. However, he was also a cruel man, and perhaps too sadistic in the use of his intellect. It would take another kind of man to truly unite the peoples of Khorvaire."
The History of The Peoples of Khorvaire by Professor Saan of Morgrave University.