Explanation:

The alliance began to form in 1936. First, on October 15, 1936 Germany and Italy signed a friendship treaty that formed the Rome-German Axis. It was after this treaty that Italian dictator Benito Mussolini used the term Axis to refer to their alliance. Shortly after this, on November 25, 1936, Japan and Germany both signed the Anti-Comintern Pact, which was a treaty against communism.

An even stronger alliance was signed between Germany and Italy on May 22, 1939 called the Pact of Steel. This treaty would later be called the Tripartite Pact when Japan signed it on September 27, 1940. Now the three main Axis Powers were allies in the war.