The Crusades were in response to the Arab conquerors of the Holy Land and their refusal to let Christian pilgrims worship at their holy sites. In fact, it was the Arab/Muslim conquerors that militarily subdued the indigenous Christian regions of Palestine, Syria, Egypt, North Africa, Spain, and later Asia Minor and the Balkans. These regions had long established Christian populations, and the Christians in these occupied lands were forced to endure what can only be described as a low-tech long-term Holocaust at the hands of the Arab-Muslim occupiers. This genocide, stretching over centuries, would reach its bloody crescendo in the early part of the 20th century with the annihilation of millions of Christian Armenians, Assyrian Christians, and the ancient Christian Greek population of Turkey.