The population is increasing. And it's in this context that the emperor of the Byzantines, the emperor of the Eastern Roman Empire, looks for help. Emperor Alexios I sends a delegation, sends an ambassador to Pope Urban II, and he essentially asks for some mercenaries to help him retake some of Anatolia from the Muslims. Well, Pope Urban II sees an opportunity here. It's been roughly half a century since the Great Schism. He has his own internal struggles going on and struggles with some neighboring states. He sees this potentially as an opportunity to focus attention elsewhere.