The 13th century crusades were an attemp by Catholics from Europe to conquer Jerusalem for the church.
As part of a broader turf war between "Christian" kingdoms of Europe and the "Moorish" kingdoms of the Middle East for land in and around the Mediterranean. The fixation on Jerusalem was ideological, but since you needed to occupy the Mediterranean coastline to manage it, the fight had a great deal of material economic consequence. The English crusading down south just so happened to also have a vested interest in sailing past the Iberian Peninsula without getting picked off by Barbary Pirates.
As part of a broader turf war between "Christian" kingdoms of Europe and the "Moorish" kingdoms of the Middle East for land in and around the Mediterranean. The fixation on Jerusalem was ideological, but since you needed to occupy the Mediterranean coastline to manage it, the fight had a great deal of material economic consequence. The English crusading down south just so happened to also have a vested interest in sailing past the Iberian Peninsula without getting picked off by Barbary Pirates.