Today, on August 26, 1071, one of history’s most decisive battles took place at Manzikert, initiating the creation of the modern state of Turkey atop formerly Christian Asia Minor. The story, which follows, is instructive.In 1019, “the first appearance of the bloodthirsty beasts… the savage nation of infidels called Turks entered Armenia,” in eastern Anatolia, “and mercilessly slaughtered the Christian faithful with the sword,” writes a chronicler. In the ensuing years and decades, virtually the whole of Armenia was decimated: hundreds of thousands were slaughtered or enslaved, and thousands of churches torched or desecrated, including by being turned into mosques:...