In the Gospels, the disciples come to Jesus and ask him about the End of Days. He’s got bad news and good. First, everything was going to go hell, so to say: “And Jesus answered . . . many shall come in my name, saying, I am Christ; and shall deceive many. And ye shall hear of wars and rumours of wars: see that ye be not troubled: for all these things must come to pass, but the end is not yet. For nation shall rise against nation, and kingdom against kingdom: and there shall be famines, and pestilences, and earthquakes, in divers places. All these are the beginning of sorrows.” (Mathew 24: 4-8 KJV). But then, Jesus says, things are going to get a lot better for those who hold fast: “But he that shall endure unto the end, the same shall be saved. And this gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come.” (Mathew 24: 13-14 KJV) Now you may think all of this is allegory. But people in the Middle Ages didn’t. They took it to heart and acted on it, most significantly by launching the Crusades (which, as you know, were many). That’s one of the many interesting messages of Brett Whalen‘s new book Dominion of God: Christendom and Apocalypse in the Middle Ages (Harvard UP, 2009). The Christians believed that, as Jesus said, the gospel would be preached everywhere before the End. Well circa 1100 it was hardly preached everywhere. It wasn’t even preached in the Holy Land, which was of course held by Infidels. Clearly something had to be done about that. Thus was the Church of Christ turned into the Army of God, all in the name of speeding the End of Time. As Brett points out, things got a little out of hand in the period that followed. Turns out that not having God on your side can mean trouble. Read the book and find out how.Please become a fan of “New Books in History” on Facebook if you haven’t already. Learn more about your ad choices. Visit megaphone.fm/adchoices