The aftermath of the Celali Rebellion witnessed a great nomad invasion into large parts of Anatolia, Syria, and northern Iraq. Tribes once restricted to mountainous or desert land in the eastern provinces poured almost to the western end of Turkey. The movement proved sudden, surprising, and – for over two hundred years – irreversible. As discussed in previous chapters, a combination of state policy and demographic expansion had gradually forced back the bounds of nomadic pastoralism since the early 1500s, paving the way for settled villages. Tribal resistance, though persistent, had been unable to stop the encroachment of farming into former grazing lands. The Little Ice Age crisis, however, offered the nomads a chance to push back. In the space of a few years, this pastoral movement virtually wiped out the settlement gains of a century. As in past disasters, both human and environmental factors played important roles.