They’ll be back

“The campaigns of the Mongol armies were the last and the most destructive in the long lines of nomad invasions from the steppes. In just over fifty years they conquered half the known world and it was only their adherence to tribal traditions and the rivalry of their princes that denied them the rest of it. Western Europe and Islam were not saved [on the battlefield], they were saved when Mongol armies halted in their moment of triumph. If [the Mongol leaders] had not died when they did, the largest empire that the world has ever known would have been bounded in the west not by the Carpathians and the Euphrates, but by the Atlantic Ocean.” – James Chambers, The Devil’s Horsemen