The title says “effective ruler” and I’m not sure how you got so far off track. You should be thinking of Machiavelli, not Juan Carlos. Edward was able to hold

The title says “effective ruler” and I’m not sure how you got so far off track. You should be thinking of Machiavelli, not Juan Carlos. Edward was able to hold on to power despite the strength of a true rival... things that would lead him to get help from William, and we all know how that story goes. But a lesser king could have easily found himself on a pike in the eleventh century.