There never was a more brilliant cohort of Russian historians in the English-speaking world, nor will there ever likely be again. Five extraordinary students in Michael Karpovich's seminars of 1946-1947 at Harvard University went on to dominate the Russian historical field in America for some four decades. 2 They took the lead at the three preeminent centers of Russian historical study in postwar America-Martin Malia and Nicholas Riasanovsky at Berkeley, Leopold Haimson and Marc Raeff at Columbia, and Richard Pipes at Harvard. At these institutions, they collectively trained the overwhelming majority of prominent Russian historians and between them much of the broader field. They also opened or creatively developed many fields and periods of Russian historical inquiry-more than any other cohort then or since.This study is deeply personal. At Harvard in the late 1980s and early 1990s, my graduatestudent colleagues and I often debated who were the "most important" historians of Russia. Our lists usually included all five. After I finished my PhD in 1992, I frequently exchanged letters with Pipes, an exemplary correspondent. The Pleiade continued to fascinate me, the term suggesting itself quite naturally: Terrence Emmons around the same time referred to the cohort as "a remarkable pleiad." 3 In a diary entry I penned on June 9, 1995, I had already laid out the basic premise of this study. "In the field of Russian history in America," I wrote,