What is the significance of the first crusade?

Answer 1

The Crusades had three goals, depending on the underlying motives of each of the main players.

To the general public, its goal was 'freeing the Holy City', the rallying cry used in public by Pope Urban II. In reality, no-one until then had been much bothered that it had been a Muslim-ruled city for the last three hundred years. Christian pilgrims had always been welcome tourists, getting guided tours and being shown lots of artifacts connected to Christ that had miraculously "survived" over a thousand years. The Arab tour guides were even happy to sell you a piece of the True Cross or a branch of the Burning Bush if you were prepared to pay their price.

Pope Urban's real and underlying second goal - apart from this 'public relations'-reason so to speak - was that by rallying military support for a much-pressed Byzantine Emperor Alexios I, he hoped to settle a long-running dispute in his favor, namely the schism between Roman Catholics and Orthodox Christians, who refused to acknowledge the Pope's position as Head of all Christendom. And he needed the Byzantine Emperor's dependence and gratitude for that.

Emperor Alexios' had a third goal in mind for which he wanted and supported the Crusade. The generally peaceful Arab rulers of Palestine had been supplanted by the Arab Seljuqs, a much more warlike Empire that had started to put much pressure on the Byzantine Empire's southern borders. Alexios reckoned that the help of a professional Crusader army might well tip the scales in his favor. And he understood that by stressing (or inventing) the hardships and cruel treatment of pilgrims he might motivate the Christian knights to come over.

The First Crusade was the only one to ever reach its goal. Its Crusader Army was reasonably well-organized and it managed to 'free' Jerusalem, if only temporarily. Pope Urban's real goal of resolving the Schism in his favor was never realized however, since certainly the later Crusades were often badly organized and needed much help from the Byzantines instead of the other way around.

Byzantium came to mostly regret bitterly its call for help from the Crusaders. It (rightly) considered most Crusader armies undisciplined mobs of untrained soldiers and hangers-on who only cost them much money and effort to sustain and help on their way, usually to defeat. Moreover, their commercial competitors - especially Venice - used the Crusades as a pretext to force the Byzantines out of their markets; one 'Crusade' even was completely and exclusively directed against Constantinople, led by the Doge of Venice as its commander.