The next phase of history in the Orthodox East was overshadowed by the break with the western church (the Great Schism) in 1054, the sacking of Constantinople by the Crusaders in 1204, and the threat of conquest by the Turks which finally materialised in 1453. The place which encapsulates this time is Mount Athos, a concentration of monastic settlements in Greece. In 963 the first monasteries were founded on Mount Athos, and this become the centre of Eastern Orthodox monasticism. A seminal figure at this time was Gregory Palamas from Thessalonica who spent time at Athos. His practice of silent prayer epitomised Orthodox spirituality. Palamas undergirded this mystical experience by a theology which differentiated God's essence from his energies. God-in-himself in his divine essence is unknowable, however we can participate in God's uncreated "energies" (action) - a process of gradual participating in the divine energies culminating in the goal of "theosis". ...