Montesquieu
 

XXI.15 On commerce since the weakening of the Romans in the west

The Mohammedans appea­red, conque­red, and split up. Egypt had her own sove­rei­gns ; she conti­nued to engage in the Indian trade. Mistress of that coun­try’s mer­chan­dise, she attrac­ted the wealth of all the others. Her sul­tans were the most power­ful prin­ces of those times : we can see in his­tory how, with a cons­tant and well-applied force, they hal­ted the ardor, the fury and the impe­tuo­sity of the Crusaders.