Final answer:
Popes have called for actions based on the needs and challenges of the time, such as Pope Urban II responding to a request for aid and initiating the First Crusade, or Pope Martin V moving the papacy back to Rome to re-establish its prominence.
Step-by-step explanation:
The reason the Pope calls Francesco back would depend on the historical context being referred to. However, in the context provided, Popes have often called for aid or made significant changes based on the political and religious circumstances of their time.
For example, Pope Urban II called for the First Crusade in response to the help requested by Byzantine Emperor Alexios I to fight against the Seljuks and as a way to heal the schism between the Western and Eastern Churches. Similarly, in the 14th century, the papacy was moved back to Rome by Pope Martin V as part of a wide-ranging effort to restore and enhance the city's spiritual and architectural grandeur, as well as the Catholic Church's influence.