Some of the views we hear today about the Crusades is that they were predatory exploitation adventures purely against Islam with a view to (modern) colonialism.
Nothing could be further from the truth. Rodney Stark's book God's Battalions gives a deeply researched rebuttal to the tendentious journalistic view that we have portrayed for us today: the Crusaders went at great personal cost to prevent the domination of the 'Holy Land' by Muslims who raided and destroyed Christian settlements and preyed on pilgrims.
That got me onto the Crusades, and I've pulled a book from my shelves that I bought in 1982: Memoirs of the Crusades by Villehardouin and De Joinville. They are contemporary accounts of a later crusade, the fourth, I think. Should be good.
But what about the 'Holy Land'? At first I thought that the particulars of place and its history are spiritually irrelevant. But then not so. Christianity is almost unique (well, actually unique, setting aside the assertions of the pagans) in being able to attach events of spiritual significance to time, place, and real people; retaining the connections we thus have with God's acts and the world we are in is significant.