who was the first king to go on crusade, and what impact did it have on the rest of christian europe and how was it viewed? did any other european king get "jealous"
First Crusade: No kings
Second Crusade: Holy Roman Emperor Conrad III and King Louis VII of France
Third Crusade: King Richard "Lionheart" of England, King Philip Augustus of France, Holy Roman Emperor Frederick I Barbarossa*.
Two things to keep in mind. First, I've only listed the kings who actually went to the Holy Land; many more provided material support for the Crusades even if they did not go themselves. Second, the Crusades were not exclusive to the Holy Land. The Second Crusade in particular involved a lot of fighting in the Iberian Peninsula (modern-day Spain/Portugal).
Note: Barbarossa never made it to the holy land - he drowned in the Goksu River near Tarsus.