What was the purpose of the first crusade? What was the purpose of the third crusade?

What was the purpose of the first crusade? What was the purpose of the third crusade? What was the purpose of the fourth crusade?

The goal of the first crusade was the liberation of the Holy Sepulcher.

The purpose of the third crusade was the threat from the Muslim states, that is, the crusaders came out to defend their kingdoms in Muslim lands.

The purpose of the fourth crusade was to seize the lands of Egypt.

Ultimately, virtually all crusades turned into a war for gold and land. Most European feudal lords did not care about the Christian goal of the campaign, but personal gain.