A lot has been written about the Crimean War of 1853-1856, but it still remains an "unknown war" for us. The fighting was conducted not only in the Crimea, they unfolded in the Caucasus, in the Danube principalities, in the Baltic, Black, White and Barents Seas, and even in Petropavlovka-Kamchatsky, besieged by the Anglo-French squadron. In fact, it was a world war in which Russia alone opposed the coalition of Great Britain, France and the Ottoman Empire and Austria-Hungary supporting them. "The causes of the Crimean War, the strangest and most unnecessary in world history, are so confused and intertwined that they do not allow a simple definition," writes Prince Alexis Trubetskoy, born in 1934 in a family of Russian emigrants in Paris and who became a professor in Canada. The author makes extensive use of materials from European archives that are not available to Russian historians. He is not only trying to figure out what nevertheless led to the massacre, but also gives an objective picture of the era that made the Crimean War possible.