Anatomical study of the brain of Vladimir Ilyich Lenin, the intellectual leader of the Russian October revolution, was conducted in an unusual context. Lenin died in 1924, at 54 years of age, as a consequence of progressive cerebrovascular disease. The eminent German neuroscientist Oskar Vogt (1870-1959) was requested by the Soviet government to examine Lenin's brain; an Institute for Brain Research, directed by Vogt, was founded for this purpose in Moscow. Tens of thousands of sections were cut serially through Lenin's brain. In his official report in 1929, Vogt adduced that pyramidal neurons of layer III in several areas of Lenin's cerebral cortex were exceptionally large and numerous. Based on his opinion that these cells might subserve "associative thinking," Vogt apparently believed that this structural peculiarity could account for the strikingly acute and penetrating mental processes that had characterized Lenin's personality. Vogt's scientific activity, the cultural and political context of the study of Lenin's brain, and its modern implications are discussed briefly.