How does the call for a crusade demonstrate the influence of the pope and the catholic church

The Crusades were a series of expeditions and religious wars that were encouraged by the Latin Church in the Medieval period. Their objective was to "recover" the Holy Land from Muslim rule. The Crusades allow us to clearly see the influence of the Pope and of the Catholic Church. As the war required thousands of soldiers, the participation and encouragement of many kings, and a massive amount of economic resources, it is clear that the Church enjoyed enormous political and economic power during this time period.

the romans were initially interested in expansion via sicily (which at that time was a cultural melting pot), part of which lay under carthaginian control. at the start of the first punic war (264-241 bc), carthage was the dominant power of the western mediterranean, with an extensive maritime empire