Trotsky Expelled from the Communist Party (1927)

Trotsky Expelled from the Communist Party (1927) marks November 12, 1927, when Leon Trotsky was expelled from the Communist Party — and Joseph Stalin became the Soviet Union’s undisputed ruler.

What happened on November 12, 1927?

On November 12, 1927, Leon Trotsky was expelled from the Communist Party. Trotsky had been Lenin’s comrade and the founder of the Red Army, one of the leading figures of the revolution — but after Lenin’s death, he lost the power struggle that followed. The expulsion was the decisive blow: it removed Trotsky from the party’s ranks and cleared the way for Joseph Stalin to become the Soviet Union’s undisputed ruler.

An expulsion from the Communist Party may sound like a bureaucratic event, but in the Soviet Union of 1927, the party was the only path to power. To be expelled was to be cast out of public life entirely. For Trotsky, the expulsion was the beginning of the end of his political career. His expulsion was followed by exile, and by assassination in Mexico in 1940 — the final chapter of a struggle he had already lost in 1927.

The Trotsky Expelled from the Communist Party (1927) moment is remembered as the day the Soviet Union’s future was decided. Two men had stood at the top of the revolution; only one remained. The party’s vote on November 12, 1927 settled the contest, and the Soviet Union would live with the consequences for generations.

Who was Leon Trotsky?

Leon Trotsky was Lenin’s comrade and the founder of the Red Army. He had been one of the most powerful and recognisable figures of the revolution, a brilliant organiser and writer who played a central role in the events that brought the Communist Party to power. Trotsky’s name was known around the world, and many had once expected him to be Lenin’s natural successor.

But after Lenin’s death, the power struggle that followed went badly for Trotsky. Joseph Stalin outmanoeuvred him — building alliances, isolating his rivals, and steadily concentrating power in his own hands. By November 1927, the contest was over. The expulsion of Trotsky from the Communist Party made it official: Stalin had won, and Trotsky had lost everything.

Why the Trotsky Expelled from the Communist Party (1927) matters

The Trotsky Expelled from the Communist Party (1927) matters because it cleared the way for Stalin’s dictatorship. With Trotsky expelled — and later exiled, and in 1940 assassinated in Mexico — Stalin faced no rival of comparable stature inside the party. The expulsion removed the last significant check on his power.

What followed is well known: Stalin’s dictatorship, the purges, and the Soviet Union’s darkest decades. The purges swept through the party, the army, and the population at large, and the terror that followed reshaped Soviet society. The expulsion of November 12, 1927 did not cause all of this by itself, but it opened the door — it cleared the way for the ruler who would carry it out.

The story of Trotsky Expelled from the Communist Party (1927) is a lesson in how history turns on single events. A vote to expel one man from a party settled the question of who would rule a vast country — and the answer shaped the lives of hundreds of millions of people, in the Soviet Union and far beyond.

How to mark Trotsky Expelled from the Communist Party (1927)

• Learn the story. Read about Leon Trotsky — Lenin’s comrade and founder of the Red Army — and about the power struggle that followed Lenin’s death. Understanding how Trotsky lost, and how Stalin won, is one of the great lessons of twentieth-century politics.
• Reflect on power and rivalry. The expulsion of November 12, 1927 shows how political contests are decided not only by ideas but by organisation, timing, and ruthlessness. Ask what made Stalin’s victory possible — and what it cost.
• Remember the consequences. Trotsky’s expulsion was followed by exile and by assassination in Mexico in 1940. And for the Soviet Union, it was followed by Stalin’s dictatorship, the purges, and the country’s darkest decades. Remembering the date means remembering where those doors led.
• Study the era. The Soviet Union of 1927 was at a turning point, and the expulsion of Trotsky is one of the clearest markers of it. Reading about this period helps explain much of what came after, at home and abroad.

Trotsky Expelled from the Communist Party (1927): frequently asked questions

When was Leon Trotsky expelled from the Communist Party?
On November 12, 1927.

Who was Leon Trotsky?
Trotsky was Lenin’s comrade and the founder of the Red Army — one of the leading figures of the revolution who lost the power struggle that followed Lenin’s death.

Who became the Soviet Union’s ruler after the expulsion?
Joseph Stalin. The expulsion cleared the way for Stalin to become the Soviet Union’s undisputed ruler.

What happened to Trotsky after the expulsion?
His expulsion was followed by exile, and by assassination in Mexico in 1940. His removal cleared the way for Stalin’s dictatorship, the purges, and the Soviet Union’s darkest decades.

Related observances

Trotsky Expelled from the Communist Party (1927) is one of the history moments remembered on this date. Read more about November 12 on November 12 Holidays, Observances and History.

Why we remember Trotsky Expelled from the Communist Party (1927)

We remember Trotsky Expelled from the Communist Party (1927) because it was the day the Soviet Union chose its ruler. November 12, 1927 settled the power struggle that followed Lenin’s death: Trotsky, Lenin’s comrade and founder of the Red Army, was expelled from the Communist Party, and Joseph Stalin became the Soviet Union’s undisputed ruler. His expulsion — followed by exile, and assassination in Mexico in 1940 — cleared the way for Stalin’s dictatorship, the purges, and the Soviet Union’s darkest decades. A single expulsion, and the course of a century changed.