At the end of World War Two, in a beautiful alpine valley in Austria, an event occurred that has been variously described as a tragedy, a betrayal, and even a war crime. Cossacks and their followers massed by the tens of thousands around Lienz expecting to be given the freedom to continue their more than 25-year struggle against Soviet oppression. Instead, they were brutally betrayed into the hands of those oppressors. During his final years in the United States, General Vyacheslav Grigroryevich Naumenko compiled numerous documents and eyewitness accounts about the incident. He published his first volume of Great Betrayal in 1962. It is mainly composed of accounts of the incident at Lienz. A second volume, relating the fate of the Cossack officers, was published in 1970. Snippets of the material Naumenko collected have been translated into English and published to great effect in various books over the years, but this is the first full translation of his first volume. It now makes the full first person accounts in Great Betrayal available in English to the remaining survivors and their many descendants, most of whom cannot read the original Russian.