The sailors at the Kronstadt naval base had long been a source of radical dissent. Mutinies had taken place during the 1905 Revolution and played an important role in persuading Nicholas II to issue his October Manifesto. The Kronstadt sailors were also active in the overthrow of Tsar in the February Revolution. A large number of the sailors were Bolsheviks and during the October Revolution they took control of the cruiser, Aurora, and sailed it up the River Neva and opened fire on the Winter Palace. According to Bertram D. Wolfe: "They jailed their officers without trial in the same hell holes that had been used to discipline them, and drowned or bloodily lynched many. Leon Trotsky later claimed: "The most hateful of the officers were shoved under the ice, of course while still alive... Bloody acts of retribution were as inevitable as the recoil of a gun."
Morgan Philips Price, a journalist working for of the Manchester Guardian, went to interview the President of the Kronstadt Workers', Soldiers' and Sailors Soviet. "I suppose you have come down here from Petrograd to see if all the stories about our terror are true. You will probably have observed that there is nothing extraordinary going on here; we are simply putting this place into order after the tyranny and chaos of the late Tsarist regime. The workmen, soldiers and sailors here find that they can do this job better by themselves than by leaving it to people who call themselves democrats, but are really friends of the old regime. That is why we have declared the Kronstadt Soviet the supreme authority in the island. The soldiers and sailors were treated on this island like dogs. They were worked from early morning till late at night. They were not allowed any recreations for fear that they would associate for political purposes. Nowhere could you study the slavery system of capitalist imperialism better than here. For the smallest misdemeanor a man was put in chains, and if he was found with a Socialist pamphlet in his possession he was shot."
By 1921 the Kronstadt sailors had become disillusioned with the Bolshevik government. They were angry about the lack of democracy and the policy of War Communism. The Soviet historian, David Shub, has argued: "On 1 March 1921, the sailors of Kronstadt revolted against Lenin. Mass meetings of 15,000 men from various ships and garrisons passed resolutions demanding immediate new elections to the Soviet by secret ballot; freedom of speech and the press for all left-wing Socialist parties; freedom of assembly for trade unions and peasant organizations; abolition of Communist political agencies in the Army and Navy; immediate withdrawal of all grain requisitioning squads, and re-establishment of a free market for the peasants."
On 28th February, 1921, the crew of the battleship, Petropavlovsk, passed a resolution calling for a return of full political freedoms. On 4th March they issued the following statement: "Comrade workers, red soldiers and sailors. We stand for the power of the Soviets and not that of the parties. We are for free representation of all who toil. Comrades, you are being misled. At Kronstadt all power is in the hands of the revolutionary sailors, of red soldiers and of workers. It is not in the hands of White Guards, allegedly headed by a General Kozlovsky, as Moscow Radio tells you."
Eugene Lyons, the author of Workers’ Paradise Lost: Fifty Years of Soviet Communism: A Balance Sheet (1967), pointed out: "The hundreds of large and small uprisings throughout the country are too numerous to list, let alone describe here. The most dramatic of them, in Kronstadt, epitomizes most of them. What gave it a dimension of supreme drama was the fact that the sailors of Kronstadt, an island naval fortress near Petrograd, on the Gulf of Finland, had been one of the main supports of the putsch. Now Kronstadt became the symbol of the bankruptcy of the Revolution. The sailors on the battleships and in the naval garrisons were in the final analysis peasants and workers in uniform."
Lenin denounced the Kronstadt Uprising as a plot instigated by the White Army and their European supporters. On 6th March, Leon Trotsky issued a statement: "I order all those who have raised a hand against the Socialist Fatherland, immediately to lay down their weapons. Those who resist will be disarmed and put at the disposal of the Soviet Command. The arrested commissars and other representatives of the Government must be freed immediately. Only those who surrender unconditionally will be able to count on the clemency of the Soviet Republic."
Trotsky then ordered the Red Army to attack the Kronstadt sailors. Felix Dzerzhinsky, the head of Cheka, was also involved in putting down the uprising. Victor Serge pointed out: "Lacking any qualified officers, the Kronstadt sailors did not know how to employ their artillery; there was, it is true, a former officer named Kozlovsky among them, but he did little and exercised no authority. Some of the rebels managed to reach Finland. Others put up a furious resistance, fort to fort and street to street.... Hundreds of prisoners were taken away to Petrograd and handed to the Cheka; months later they were still being shot in small batches, a senseless and criminal agony. Those defeated sailors belonged body and soul to the Revolution; they had voiced the suffering and the will of the Russian people. This protracted massacre was either supervised or permitted by Dzerzhinsky."
Some observers claimed that many of the victims would die shouting, "Long live the Communist International!" and "Long live the Constituent Assembly!" It was not until the 17th March that government forces were able to take control of Kronstadt. An estimated 8,000 people (sailors and civilians) left Kronstadt and went to live in Finland. Official figures suggest that 527 people were killed and 4,127 were wounded. Historians who have studied the uprising believe that the total number of casualties was much higher than this.It is claimed that over 500 sailors at Kronstadt were executed for their part in the rebellion.
Nikolai Sukhanov reminded Leon Trotsky that three years previously he had told the people of Petrograd: "We shall conduct the work of the Petrograd Soviet in a spirit of lawfulness and of full freedom for all parties. The hand of the Presidium will never lend itself to the suppression of the minority." Trotsky lapsed into silence for a while, then said wistfully: "Those were good days." Walter Krivitsky later claimed that when Trotsky put down the Kronstadt Uprising the Bolshevik government lost contact with the revolution and from then on it would be a path of state terror and dictatorial rule.
Leon Trotsky later blamed Nestor Makhno and the anarchists for the uprising. "Makhno... was a mixture of fanatic and adventurer. He became the concentration of the very tendencies which brought about the Kronstadt Uprising. Makhno created a cavalry of peasants who supplied their own horses. They were not downtrodden village poor whom the October Revolution first awakened, but the strong and well-fed peasants who were afraid of losing what they had. The anarchist ideas of Makhno (the ignoring of the State, non-recognition of the central power) corresponded to the spirit of the kulak cavalry as nothing else could. I should add that the hatred of the city and the city worker on the part of the followers of Makhno was complemented by the militant anti-Semitism."
Trotsky also accused Felix Dzerzhinsky of being responsible for the massacre: "The truth of the matter is that I personally did not participate in the least in the suppression of the Kronstadt rebellion, nor in the repressions following the suppression. In my eyes this very fact is of no political significance. I was a member of the government, I considered the quelling of the rebellion necessary and therefore bear responsibility for the suppression. Concerning the repressions, as far as I remember, Dzerzhinsky had personal charge of them and Dzerhinsky could not tolerate anyone's interference with his functions (and properly so). Whether there were any needless victims I do not know. On this score I trust Dzerzhinsky more than his belated critics."