In 1099 the Franks sieged Jerusalem. The Franks were on the side of the Chrisitians a.k.a. Crusaders, were they not?
2 answers
Yes, they were crusaders taking the holy land back (temporarily) from the Moslems.
Actually, the Crusaders were bolstering the Catholic hierarchy who needed help in retaining the popular support at that time -- not to mention the monies that came pouring in to the treasury when people thought they were "saving the Holy Land from the Infidels."