King, Kaiser, Tsar : three royal cousins who led the world to war / Catrine Clay.

Enhanced descriptions from Syndetics:

The extraordinary family story of George V, Wilhelm II, and Nicholas II: they were tied to one another by history, and history would ultimately tear them apart.

Known among their families as Georgie, Willy, and Nicky, they were, respectively, the royal cousins George V of England, Kaiser Wilhelm II of Germany, and Nicholas II of Russia--the first two grandsons of Queen Victoria, the latter her grandson by marriage. In 1914, on the eve of world war, they controlled the destiny of Europe and the fates of millions of their subjects. The outcome and their personal endings are well known--Nicky shot with his family by the Bolsheviks, Willy in exile in Holland, Georgie still atop his throne. Largely untold, however, is the family saga that played such a pivotal role in bringing the world to the precipice.

Drawing widely on previously unpublished royal letters and diaries, made public for the first time by Queen Elizabeth II, Catrine Clay chronicles the riveting half century of the royals' overlapping lives, and their slow, inexorable march into conflict. They met frequently from childhood, on holidays, and at weddings, birthdays, and each others' coronations. They saw themselves as royal colleagues, a trade union of kings, standing shoulder to shoulder against the rise of socialism, republicanism, and revolution. And yet tensions abounded between them.

Clay deftly reveals how intimate family details had deep historical significance: the antipathy Willy's mother (Victoria's daughter) felt toward him because of his withered left arm, and how it affected him throughout his life; the family tension caused by Otto von Bismarck's annexation of Schleswig and Holstein from Denmark (Georgie's and Nicky's mothers were Danish princesses); the surreality surrounding the impending conflict. "Have I gone mad?" Nicholas asked his wife, Alexandra, in July 1914, showing her another telegram from Wilhelm. "What on earth does Willy mean pretending that it still depends on me whether war is averted or not?" Germany had, in fact, declared war on Russia six hours earlier. At every point in her remarkable book, Catrine Clay sheds new light on a watershed period in world history.