Adolf Hitler orders the Luftwaffe to be re-formed, violating the provisions of the Treaty of Versailles.

The Treaty of Versailles (French: Trait de Versailles; German: Versailler Vertrag, pronounced [vza ftak] (listen)) was the most important of the peace treaties of World War I. It ended the state of war between Germany and the Allied Powers. It was signed on 28 June 1919 in the Palace of Versailles, exactly five years after the assassination of Archduke Franz Ferdinand, which led to the war. The other Central Powers on the German side signed separate treaties.

Although the armistice of 11 November 1918 ended the actual fighting, it took six months of Allied negotiations at the Paris Peace Conference to conclude the peace treaty. The treaty was registered by the Secretariat of the League of Nations on 21 October 1919.

Of the many provisions in the treaty, one of the most important and controversial was: "The Allied and Associated Governments affirm and Germany accepts the responsibility of Germany and her allies for causing all the loss and damage to which the Allied and Associated Governments and their nationals have been subjected as a consequence of the war imposed upon them by the aggression of Germany and her allies." The other members of the Central Powers signed treaties containing similar articles.

This article, Article 231, became known as the War Guilt clause. The treaty required Germany to disarm, make ample territorial concessions, and pay reparations to certain countries that had formed the Entente powers. In 1921 the total cost of these reparations was assessed at 132 billion gold marks (then $31.4 billion or £6.6 billion, roughly equivalent to US$442 billion or UK£284 billion in 2022).

Prominent economists such as John Maynard Keynes declared the treaty too harsha "Carthaginian peace"and said the reparations were excessive and counter-productive. On the other hand, prominent Allied figures such as French Marshal Ferdinand Foch, criticized the treaty for treating Germany too leniently. This is still the subject of ongoing debate by historians and economists.

The result of these competing and sometimes conflicting goals among the victors was a compromise that left no one satisfied. In particular, Germany was neither pacified nor conciliated, nor was it permanently weakened. The problems that arose from the treaty would lead to the Locarno Treaties, which improved relations between Germany and the other European powers, and the re-negotiation of the reparation system resulting in the Dawes Plan, the Young Plan, and the indefinite postponement of reparations at the Lausanne Conference of 1932. The treaty has sometimes been cited as a cause of World War II: although its actual impact was not as severe as feared, its terms led to great resentment in Germany which powered the rise of the Nazi Party.

Although it is often referred to as the "Versailles Conference", only the actual signing of the treaty took place at the historic palace. Most of the negotiations were in Paris, with the "Big Four" meetings taking place generally at the French Ministry of Foreign Affairs on the Quai d'Orsay.

Adolf Hitler (German: [ˈad.ɔlf ˈhɪt.lɐ] (listen); 20 April 1889 – 30 April 1945) was an Austrian-born German politician who was the dictator of Germany from 1933 until his death in 1945. He rose to power as the leader of the Nazi Party, becoming the chancellor in 1933 and then assuming the title of Führer und Reichskanzler in 1934. During his dictatorship, he initiated World War II in Europe by invading Poland on 1 September 1939. He was closely involved in military operations throughout the war and was central to the perpetration of the Holocaust, the genocide of about six million Jews and millions of other victims.

Hitler was born in Austria-Hungary and was raised near Linz. He lived in Vienna later in the first decade of the 1900s and moved to Germany in 1913. He was decorated during his service in the German Army in World War I. In 1919, he joined the German Workers' Party (DAP), the precursor of the Nazi Party, and was appointed leader of the Nazi Party in 1921. In 1923, he attempted to seize governmental power in a failed coup in Munich and was imprisoned with a sentence of five years. In jail, he dictated the first volume of his autobiography and political manifesto Mein Kampf ("My Struggle"). After his early release in 1924, Hitler gained popular support by attacking the Treaty of Versailles and promoting pan-Germanism, anti-Semitism and anti-communism with charismatic oratory and Nazi propaganda. He frequently denounced international capitalism and communism as part of a Jewish conspiracy.

By November 1932, the Nazi Party held the most seats in the German Reichstag, but did not have a majority. As a result, no party was able to form a majority parliamentary coalition in support of a candidate for chancellor. Former chancellor Franz von Papen and other conservative leaders persuaded President Paul von Hindenburg to appoint Hitler as chancellor on 30 January 1933. Shortly after, the Reichstag passed the Enabling Act of 1933 which began the process of transforming the Weimar Republic into Nazi Germany, a one-party dictatorship based on the totalitarian and autocratic ideology of Nazism. Hitler aimed to eliminate Jews from Germany and establish a New Order to counter what he saw as the injustice of the post-World War I international order dominated by Britain and France. His first six years in power resulted in rapid economic recovery from the Great Depression, the abrogation of restrictions imposed on Germany after World War I, and the annexation of territories inhabited by millions of ethnic Germans, which gave him significant popular support.

Hitler sought Lebensraum (lit. 'living space') for the German people in Eastern Europe, and his aggressive foreign policy is considered the primary cause of World War II in Europe. He directed large-scale rearmament and, on 1 September 1939, invaded Poland, resulting in Britain and France declaring war on Germany. In June 1941, Hitler ordered an invasion of the Soviet Union. By the end of 1941, German forces and the European Axis powers occupied most of Europe and North Africa. These gains were gradually reversed after 1941, and in 1945 the Allied armies defeated the German army. On 29 April 1945, he married his longtime lover, Eva Braun, in the Führerbunker in Berlin. Less than two days later, the couple committed suicide to avoid capture by the Soviet Red Army. Their corpses were burned.

Under Hitler's leadership and racially motivated ideology, the Nazi regime was responsible for the genocide of about six million Jews and millions of other victims whom he and his followers deemed Untermenschen (subhumans) or socially undesirable. Hitler and the Nazi regime were also responsible for the killing of an estimated 19.3 million civilians and prisoners of war. In addition, 28.7 million soldiers and civilians died as a result of military action in the European theatre. The number of civilians killed during World War II was unprecedented in warfare, and the casualties constitute the deadliest conflict in history.

Hitler's actions as Führer of Germany are almost universally regarded as gravely immoral. Prominent historian and biographer Ian Kershaw describes Hitler as "the embodiment of modern political evil", and that "never in history has such ruination—physical and moral—been associated with the name of one man".