Top Photo: Meeting of Benito Mussolini and Adolf Hitler at the station at the German headquarters in August 1941. Central Achives of Italy

World War II was the most destructive conflict in human history and claimed the lives of millions of people all over the world. It was a complicated war that included entire countries being occupied, shifting alliances, and the redrawing of national borders.  

Answering the question of which side a country was on in the war can be surprisingly complicated and often depends on the period. This article provides an overview of the countries on the Axis side of the war, some of the key leaders, and the major events that shaped the political landscape of the war.

The Axis Powers

The Axis powers were initially united by a treaty called the Anti-Comintern Pact of 1936. The term “Comintern” referred to the Communist International, a global organization of communist parties working to foment worldwide revolution led by the Soviet Union. The initial signers of the Anti-Comintern Pact were Germany and Japan.

The Anti-Comintern Pact was motivated by Germany and Japan’s shared view of the international order in the late 1930s. Adolf Hitler had taken power in Germany in 1933, first as chancellor and then with the newly created title of Führer. Over the next few years, Hitler consolidated power, rearmed the country in violation of the Treaty of Versailles, and took an aggressive stance toward his European neighbors. 

In Asia, Japanese Emperor Hirohito’s government was increasingly dominated by militant nationalists. In 1931, Japan invaded the Chinese region of Manchuria and established a puppet state called Manchukuo. Japan’s expansion in the east would inevitably target European colonial possessions in the region. In addition, both Germany and Japan were avowedly anticommunist, both had banned the Communist Party domestically, and both might be physically threatened by the Soviet Union. 

Negotiations for a formal treaty began in summer of 1936, and the Anti-Comintern Pact was officially signed on November 25, 1936. Italy’s Fascist government under Benito Mussolini joined the treaty in 1937. This new alliance was nicknamed the Rome–Berlin–Tokyo Axis, or the Axis for short. In September 1940—a year after the start of World War II—Germany, Italy, and Japan signed the Tripartite Act pledging mutual military and economic support for one another. Additional countries signed the Tripartite Pact before and during the war, including Romania, Hungary, and Bulgaria, contributing to the Axis military effort for much of the war. 

Despite this complicated history, the countries most commonly referred to as the “Axis powers” are the original signatories of the Tripartite Pact: Germany, Japan, and Italy. However, the term can be more loosely applied to any country that signed the Tripartite Pact during the war. 

Outcomes from World War II

All the Axis powers were defeated in the course of World War II and left the conflict at different times. Mussolini was deposed following the invasion of Sicily in 1943, and Italy formally changed sides and joined the Allies later that year, though Rome would not be liberated until June 1944. Hitler initially propped up Mussolini as the head of a German puppet state in the north of Italy, but the Allied advance continued and in 1945 the former Italian dictator was captured and killed by partisans. Facing a Soviet onslaught in the East, Hungary, Romania, and Bulgaria each attempted to exit the war or join the Allies in 1944 as the Red Army approached and eventually occupied them.

Soviet forces entered Berlin in April 1945, prompting Hitler to commit suicide. Germany formally surrendered to the Allies on May 8, 1945, ending the war in Europe. Japan surrendered in August 1945 following the atomic bombings of Hiroshima and Nagasaki, marking the end of the Axis and the war itself. The postwar world would be shaped by the victorious Allies. In April 1945, the United Nations was formalized into the permanent international organization that bears the same name today.