Montesquieu

A monar­chi­cal state should be of medium size. If it were small, it would form as a repu­blic ; if it were very exten­sive, the prin­ci­pal mem­bers of the state, great in them­sel­ves, not being under the prince’s eye, having their court out­side his court, assu­red moreo­ver against swift exe­cu­tions by the laws and ethos, could cease to obey ; they would not fear a punish­ment that is too slow and too dis­tant.

Thus Charlemagne, when he had barely foun­ded his empire, had to divide it up : either because the gover­nors of the pro­vin­ces would not obey, or to make them obey bet­ter it was neces­sary to divide the empire into seve­ral king­doms.

After the death of Alexander, his empire was divi­ded. How could those gran­dees of Greece and Macedonia, free, or at least chiefs of the conque­rors dis­tri­bu­ted throu­ghout that vast conquest, have obeyed ?

After the death of Attila, his empire was dis­sol­ved : so many kings who were no lon­ger contai­ned could not take up chains again.

The prompt esta­blish­ment of unli­mi­ted power is the remedy which in these cases can pre­vent dis­so­lu­tion, a new mis­for­tune after that of expan­sion !

Rivers flow to blend into the sea ; monar­chies go and lose them­sel­ves in des­po­tism.