Why weren't Crusaders Kingdoms under the Germanic and French crown?

May 2019
Interestingly imo, at least one of the Crusader states fell under nominal Mongol sovereignty. Bohemond VI of Antioch became a tributary of Hulegu Khan, and I believe Antioch contributed some troops to Mongol campaigns in Syria during the 1260s.


Ad Honorem
Jan 2017
the bit about the Jerusalem crown being offered to the emperor
vague memories but I think it was the Grand Master of the Teutonics Hermann von Salza
who was both the Pope and the emperor good friends good friend ( an impossible combination ) who suggested it

the purpose was to get some solid support for Outremer ,
the Crusading kingdoms didn't have the men or resources to stand on their own against an unified Muslim Near East

anyone can proclaim himself King ,
for the purpose of making matrimonial alliances , a formal status was necessary
in Europe the tittle had to be recognized by both the Pope and the Emperor to be considered first class
to be declared a prince only one of them was enough