Italy was the first to ally Germany followed by Japan in 1968 conforming the axis powers.
The "Axis powers" formally received the name after the signature of the Tripartite Pact by Germany, Italy, and Japan on 27 September 1940, in Berlin. The pact was subsequently joined by Hungary (20 November 1940), Romania (23 November 1940), Slovakia (24 November 1940), and Bulgaria (1 March 1941).
The Axis grew out of the diplomatic efforts of Germany, Italy, and Japan to secure their own specific expansionist interests in the mid-1930s.
