Constitutional monarchy was a concept that emerged from the political revolutions of the Age of Enlightenment. Why did the kings of Europe usually resist this idea and work to prevent it from affecting their kingdoms? Kings in Europe did not care about the problems of merchants or anyone else in their kingdoms--they just liked having power.

Constitutional monarchies required kings to follow the same laws as others--and most kings felt they were above the laws of the land,

Kings in Europe tended to look for fights wherever they could find them--after all, that's how they became kings.

Kings in Europe were afraid that a constitution would require them to give away all of their wealth to support the kingdom's poor.