Title: Why were the Crusades unsuccessful? - Quora
Headings: Why were the Crusades unsuccessful?
Why were the Crusades unsuccessful?
Anonymous

Content: Having said that, this crusading army progressed through Anatolia down to Jerusalem and in their wake Alexios regained control of important cities such as Nikea. From this perspective, the First Crusade was a moderate success for him. However, if we fast-forward in time, it is widely considered that the Fourth Crusade (1202-1204) completely crippled the Byzantine Empire and led to the collapse of Constantinople in 1453 becoming a when rather than an if. So long-term, the crusades were unsuccessful for the Byzantines as they led to the destruction of their empire rather than the restoration of it. Papal Motivations
The First Crusade was initiated in Western Europe by Pope Urban II (1088-1099). While this was off the back of the Byzantine envoys turning up, no-one seriously thinks that the Pope promoted the crusade for purely selfless reasons to help the Byzantines. At the very least he wanted to re-establish Roman hegemony over the Eastern Orthodox Church, which in 1054 had split from Rome, a schism which remains to this present day. In addition to this it seems that he was keen to increase the power of the papacy, as during this century the investiture controversy had really kicked off (should the king or the church appoint bishops, oddly enough they disagreed on the answer). A crusade would promote loyalty amongst Western Christendom and be a rallying cry. In addition to this was the awkward fact that since the Islamic invasion of the late seventh and early eighth century, the original Christian lands of the Middle East were under Muslim rule and so this needed rectifying.