The problem might be that, by definition, the most powerful person in the world will be a politician.

I, for example, would consider powerful kings and emperors to be politicians.

Would you count the Pope as a politician? Considering his role and job description it is debateable.

Unqualified presupposition: There was a point in time that a subject entity was more "powerful" than the strongest sovereignty in the world (seeing as you've included every leader ever in your deffinition of "polititian").

I believe the question is flawed. I'd like to support this statement with a quote from ''The twenty years crisis'' by Edward Hallett Carr.

/Politics are, then, in one sense always power politics. Common usage applies the term ''political'' not to all activities of the state, but to issues involving a conflict of power. Once this conflict has been resolved, the issue ceases to be ''political'' and becomes a matter of administrative routine.

While politics cannot be satisfactorily defined exclusively in terms of power, it is safe to say that power is always an essential element of politics.

I think it would be nigh impossible to find an individual in such a place of power who is not also a politician or heavily involved in politics.