^Germany, Italy, and Japan are typically described as being the "major" (or similar) countries amongst the Axis powers. See e.g., Global Strategy, Momah, p. 71, or Encyclopedia of World War II, Tucker & Roberts, p. 102.
^ abcdeAcceded to the Tripartite Pact, generally considered Axis powers (see e.g., Facts About the American Wars, Bowman, p. 432, which includes them in a list of "Axis powers", or The Library of Congress World War II Companion, Wagner, Osborne, & Reyburn, p. 39, which lists them as "The Axis").
^With the exception of Germany and Italy, Romania was the only country where a Fascist movement came to power without foreign assistance.
^ abPuppet states installed by the Axis Powers, see, e.g., Axis Rule in Occupied Europe, Lemkin, p. 11
^Official position of wartime government was that they were a co-belligerent of the Axis against the USSR and United Kingdom during the Continuation War, but generally considered to be a member of the Axis (see e.g., Bowman, p. 432, Wagner, Osborne, & Reyburn p. 39, or Dinardo p. 95).
^Declared war on the United Kingdom and United States in alliance with Japan on 25 January 1942, generally considered to be a member of the Axis (e.g. Bowman, p. 432).
The signing of the Tripartite Pact by Germany, Japan, and Italy on 27 September 1940 in Berlin. Seated from left to right are the Japanese ambassador to Germany Saburō Kurusu, Italian Minister of Foreign Affairs Galeazzo Ciano, and Adolf Hitler.
The Axis grew out of successive diplomatic efforts by Germany, Italy, and Japan to secure their own specific expansionist interests in the mid-1930s. The first step was the protocol signed by Germany and Italy in October 1936, after which Italian leader Benito Mussolini declared that all other European countries would thereafter rotate on the Rome–Berlin axis, thus creating the term "Axis". The following November saw the ratification of the Anti-Comintern Pact, an anti-communist treaty between Germany and Japan; Italy joined the Pact in 1937, followed by Hungary and Spain in 1939. The "Rome–Berlin Axis" became a military alliance in 1939 under the so-called "Pact of Steel", with the Tripartite Pact of 1940 formally integrating the military aims of Germany, Italy, Japan, and later followed by other nations. The three pacts formed the foundation of the Axis alliance.
At its zenith in 1942, the Axis presided over large parts of Europe, North Africa, and East Asia, either through occupation, annexation, or puppet states. In contrast to the Allies, there were no three-way summit meetings, and cooperation and coordination were minimal; on occasion, the interests of the major Axis powers were even at variance with each other. The war ended in 1945 with the defeat of the Axis powers and the dissolution of their alliance. As in the case of the Allies, membership in the Axis was fluid, with some nations switching sides or changing their degree of military involvement over the course of the war.
Particularly within Europe, the use of the term "the Axis" primarily refers to the alliance between Italy and Germany, though outside Europe it is normally understood as including Japan.