The model of the Hospitaller or the Knights of St John Compound in Acre in the 13th century, Acre, Israel. The size and the fortification of the compound, which also served as the headquarters for the Order of St John, shows economic and political importance of presence in the Holy Land for the Order during the Crusades; economic, because of being a mediator in trade between the Levant and Europe and a pilgrimage to the Holy Land, and political, because of being a pillar of support for Christian Europe rulers as a military protection against Muslims in the Kingdom of Jerusalem.