His financial resources were greater than those of any other European ruler.
European rulers saw it as the color of power, dignity, humility and temperance.
European rulers had long since ceased to take Charles seriously.
Western European rulers determined to find new trade routes of their own.
There was a striking increase in the attention paid by most European rulers to military details of all kinds.
He also asked the papacy and the Western European rulers for help.
Both hypotheses could be right, corresponding to the contemporary practice of European rulers.
He achieved some results, getting modest help from European rulers.
Realizing how this would upset the balance of power, the other European rulers were outraged.
Those systems were established during the colonial period and have been reinforced since these former colonies became independent of their European rulers.