Full Idea
In a sense, nobility is one part of the essence of monarchy, whose fundamenta maxim is: 'without a monarchy, no nobility; without a nobility, no monarchy'. There are, of course, despots, but they are something else.
Gist of Idea
The nobility are an indispensable part of a monarchy
Source
Baron de Montesquieu (The Spirit of the Laws (rev. 1757) [1748], 02.04)
Book Reference
Montesquieu,Baron de: 'Selected Political Writings', ed/tr. Richter,Melvin [Hackett 1990], p.122
A Reaction
Hence the worst vice associated with a monarchy is patronage, even when the monarch is weak and 'constitutional'.