This book is a legal document of great historical significance. In 1936-1938, during the period of the Great Purges, in which millions died, there were three "show trials" in Moscow. 1. The first trial was of 16 members of the so-called "Trotskyite-Zinovievite Terrorist Centre", held in August 1936, at which the chief defendants were Grigory Zinoviev and Lev Kamenev, two of the most prominent former party leaders. All were sentenced to death and were promptly executed. 2. The second trial in January 1937 involved 17 lesser figures including Karl Radek, Yuri Piatakov and Grigory Sokolnikov. Thirteen of the defendants were shot immediately. The rest received sentences in labor camps, where they were shot a few years later. 3. The third trial, in March 1938, included 21 defendants alleged to belong to the so-called "Bloc of Rightists and Trotskyites", led by Nikolai Bukharin, former head of the Communist International, former Prime Minister Alexei Rykov, Genrikh Yagoda, Christian Rakovsky and Nikolai Krestinsky. All of the leading defendants were executed. All of the defendants in these "trials" were prominent personalities, including former members of the Politburo and old Bolsheviks whose credentials as revolutionaries could not be questioned. The charges against them were that they had received messages from Trotsky who was in such places as Copenhagen and Mexico City, directing them to overthrow the Government of the Soviet Union and restore Capitalism. Although the charges were inherently ridiculous, a committee of old leftists formed in Mexico City to examine them. They had as their star witness Trotsky himself plus one of his wives and one of his sons who had not been killed yet, plus all of Trotsky's papers. Through these documents, they were able to prove that the charges in the Moscow show trials were false. Trotsky himself was assassinated in Mexico City on August 21, 1940, two years after this Dewey Commission Report had been published.