The first impression that one gets of a ruler and of his brains is from seeing the men that he has about him.

Niccolò Machiavelli (1469-1527) Italian politician, philosopher, political scientist
The Prince, ch. 22 (1513) [tr. Ricci (1903)]

Variant: "The first method for estimating the intelligence of a ruler is to look at the men he has around him!"