The Huns, invading through Dariali Gorge on the modern-day border between Russia and Georgia in AD 395 and 515, spread terror across the late antique world. Was this the prelude to the apocalypse? Prophecies foresaw a future Hunnic onslaught, via the same mountain pass, bringing about the end of the world. Humanity's fate depended on a gated barrier deep in Europe's highest and most forbidding mountain chain.
Centuries before the emergence...