World War II | Facts, Summary, History, Dates, Combatants, & Causes
World War II was a conflict that involved virtually every part of the world during 1939–45. The main combatants were the Axis powers ...
Axis powers
The main combatants were the <anchor>Axis powers</anchor> (Germany, Italy, and Japan) and the Allies (France, Great Britain, the United States, the Soviet Union, and, to a lesser extent, China).
Axis powers | Countries & History | Britannica
Axis powers \| Countries & History \| Britannica

[![Encyclopedia Britannica](https://cdn.britannica.com/mendel/eb-logo/MendelNewThistleLogo.png)](/)

Search BritannicaClick here to search

[![Encyclopedia Britannica](https://cdn.britannica.com/mendel/eb-logo/MendelNewThistleLogo.png)](/)

Search BritannicaClick here to search

[Subscribe  Now](https://premium.britannica.com/premium-membership/?utm_source=premium&utm_medium=global-nav&utm_campaign=evergreen)

[Subscribe](https://premium.britannica.com/premium-membership/?utm_source=premium&utm_medium=global-nav-mobile&utm_campaign=evergreen)

Login

- [Home](/)
- [History & Society](/History-Society)
- [Science & Tech](/Science-Tech)
- [Biographies](/Biographies)
- [Animals & Nature](/Animals-Nature)
- [Geography & Travel](/Geography-Travel)
- [Arts & Culture](/Arts-Culture)
- [Money](/money)

- [Games & Quizzes](/quiz/browse)
- [Videos](/videos)
- [On This Day](/on-this-day)
- [One Good Fact](/one-good-fact)
- [Dictionary](/dictionary)
- [New Articles](/new-articles)

[History & Society](/History-Society)

- [Lifestyles & Social Issues](/browse/Lifestyles-Social-Issues)
- [Philosophy & Religion](/browse/Philosophy-Religion)
- [Politics, Law & Government](/browse/Politics-Law-Government)
- [World History](/browse/World-History)

[Science & Tech](/Science-Tech)

- [Health & Medicine](/browse/Health-Medicine)
- [Science](/browse/Science)
- [Technology](/browse/Technology)

[Biographies](/Biographies)

- [Browse Biographies](/browse/biographies)

[Animals & Nature](/Animals-Nature)

- [Birds, Reptiles & Other Vertebrates](/browse/Birds-Reptiles-Vertebrates)
- [Bugs, Mollusks & Other Invertebrates](/browse/Bugs-Mollusks-Invertebrates)
- [Environment](/browse/Environment)
- [Fossils & Geologic Time](/browse/Fossil-Geologic-Time)
- [Mammals](/browse/Mammals)
- [Plants](/browse/Plants)

[Geography & Travel](/Geography-Travel)

- [Geography & Travel](/browse/Geography-Travel)

[Arts & Culture](/Arts-Culture)

- [Entertainment & Pop Culture](/browse/Entertainment-Pop-Culture)
- [Literature](/browse/Literature)
- [Sports & Recreation](/browse/Sports-Recreation)
- [Visual Arts](/browse/Visual-Arts)

- [Companions](/stories/companion)
- [Demystified](/stories/demystified)
- [Image Galleries](/gallery/browse)
- [Infographics](https://www.britannica.com/study/infographics)
- [Lists](/list/browse)
- [Podcasts](/podcasts)
- [Spotlight](/stories/spotlight)
- [Summaries](/summary)
- [The Forum](/stories/the-forum)
- [Top Questions](/question)
- [#WTFact](/stories/wtfact)

- [100 Women](https://www.britannica.com/explore/100women/)
- [Britannica Kids](https://kids.britannica.com/)
- [Saving Earth](https://www.britannica.com/explore/savingearth/)
- [Space Next 50](https://www.britannica.com/explore/space/)
- [Student Center](https://www.britannica.com/study/)

[Ask the Chatbot](/chatbot) [Games & Quizzes](/quiz/browse) [History & Society](/History-Society) [Science & Tech](/Science-Tech) [Biographies](/Biographies) [Animals & Nature](/Animals-Nature) [Geography & Travel](/Geography-Travel) [Arts & Culture](/Arts-Culture) [Money](/money) [Videos](/videos)

[Axis powers](https://www.britannica.com/topic/Axis-Powers)

Table of Contents


Introduction
[References & Edit History](https://www.britannica.com/topic/Axis-Powers/additional-info) [Quick Facts & Related Topics](/facts/Axis-Powers)

[Images & Videos](https://www.britannica.com/topic/Axis-Powers/images-videos)

[![Axis leaders Adolf Hitler and Benito Mussolini](https://cdn.britannica.com/62/129962-004-9D3CF970/Adolf-Hitler-Benito-Mussolini.jpg)](https://cdn.britannica.com/62/129962-050-C26B63A7/Adolf-Hitler-Benito-Mussolini.jpg)[![Track the League of Nations' continual failure to check via diplomacy the Axis powers' pre-World War II rise](https://cdn.britannica.com/31/72831-138-0F810906/events-Axis-Powers-world-war.jpg?w=400&h=225&c=crop)](/video/72831/events-Axis-Powers-world-war)[![Benito Mussolini with Adolf Hitler](https://cdn.britannica.com/64/197364-004-48EDE09F/Benito-Mussolini-Italian-Adolf-Hitler-Eastern-Front.jpg)](https://cdn.britannica.com/64/197364-050-F1D668C5/Benito-Mussolini-Italian-Adolf-Hitler-Eastern-Front.jpg)[![Learn about Japan's pre-World War II invasions, joining of the Axis powers, and attack on Pearl Harbor](https://cdn.britannica.com/37/72837-138-4AF41D73/leaders-Tripartite-Pact-Imperial-Japan-conflict-Nazi-December-1941.jpg?w=400&h=225&c=crop)](/video/72837/leaders-Tripartite-Pact-Imperial-Japan-conflict-Nazi-December-1941)

For Students


[![Germany invades Poland, September 1, 1939, using 45 German divisions and aerial attack. By September 20, only Warsaw held out, but final surrender came on September 29.](https://cdn.britannica.com/26/188426-050-2AF26954/Germany-Poland-September-1-1939.jpg?w=200&h=200&c=crop)](/quiz/pop-quiz-17-things-to-know-about-world-war-ii)

[Pop Quiz: 17 Things to Know About World War II](/quiz/pop-quiz-17-things-to-know-about-world-war-ii)

[![](https://cdn.britannica.com/mendel-resources/3-124/images/shared/default3.png?v=3.124.78)](/summary/Axis-Powers)

[Axis Powers summary](/summary/Axis-Powers)

Related Questions


- [What was the cause of World War II?](/question/What-was-the-cause-of-World-War-II)
- [What were the turning points of World War II?](/question/What-were-the-turning-points-of-World-War-II)
- [How did World War II end?](/question/How-did-World-War-II-end)
- [How many people died during World War II?](/question/How-many-people-died-during-World-War-II)
- [How did Benito Mussolini rise to power?](/question/How-did-Benito-Mussolini-rise-to-power)

Read Next


[![American soldiers in the Ardennes during the Battle of the Bulge.](https://cdn.britannica.com/92/122492-131-BA95C631/soldiers-American-Ardennes-Battle-of-the-Bulge.jpg?w=200&h=200&c=crop)](/list/9-questions-about-world-war-ii-answered)

[9 Questions About World War II Answered](/list/9-questions-about-world-war-ii-answered)

[![The First Atomic Bombs infographic, Hiroshima, Nagasaki, Japan, United States, nuclear weapon, atomic bomb, World War II, WWII](https://cdn.britannica.com/37/183537-131-42551C28/World-War-II-first-atomic-bombs-test-Los-Alamos-New-Mexico-detonation-Hiroshima-Nagasaki-Japan-1945.jpg?w=200&h=200&c=crop)](/story/discover-more-about-the-first-atomic-bombs-tested-and-used-during-world-war-ii)

[The First Atomic Bombs Tested and Used During World War II](/story/discover-more-about-the-first-atomic-bombs-tested-and-used-during-world-war-ii)

[![Iraqi Army Soldiers from the 9th Mechanized Division learning to operate and maintain M1A1 Abrams Main Battle Tanks at Besmaya Combat Training Center, Baghdad, Iraq, 2011. Military training. Iraq war. U.S. Army](https://cdn.britannica.com/38/168938-131-2FBA7C21/Soldiers-Iraqi-Army-learning-9th-Mechanized-Division-2011.jpg?w=200&h=200&c=crop)](/list/8-deadliest-wars-of-the-21st-century)

[8 Deadliest Wars of the 21st Century](/list/8-deadliest-wars-of-the-21st-century)

[![Attack on Pearl Harbor. December 7, 1941. Pearl Harbor infographic. World War II. Hawaii. United States. Japan. SPOTLIGHT VERSION](https://cdn.britannica.com/40/230940-131-CD9F0D2A/infographic-Pearl-Harbor-attack-World-War-II-1941.jpg?w=200&h=200&c=crop)](/story/attack-on-pearl-harbor-timeline)

[Attack on Pearl Harbor Timeline](/story/attack-on-pearl-harbor-timeline)

[![Nazi Germany, Nazi SS troops marching with victory standards at the Party Day rally in Nuremberg, Germany, 1933. (Schutzstaffel, Nazi Party, Nurnberg)](https://cdn.britannica.com/29/187129-131-C802A328/Nazi-Party-rally-Nurnberg-Germany-1933.jpg?w=200&h=200&c=crop)](/story/why-was-nazi-germany-called-the-third-reich)

[Why Was Nazi Germany Called the Third Reich?](/story/why-was-nazi-germany-called-the-third-reich)

Discover


[![Russian grand duchess Anastasia; undated photograph. (Anastasiya Nikolayevna, Tsar Nicholas II)](https://cdn.britannica.com/68/194168-131-CFE3851A/Anastasia.jpg?w=200&h=200&c=crop)](/story/did-duchess-anastasia-survive-her-familys-execution)

[Did Duchess Anastasia Survive Her Family’s Execution?](/story/did-duchess-anastasia-survive-her-familys-execution)

[![Bakers Dozen of Donuts, or Paczki's](https://cdn.britannica.com/78/194478-131-980A335B/Bakers-Dozen-of-Donuts-Paczki.jpg?w=200&h=200&c=crop)](/story/why-is-a-bakers-dozen-13)

[Why Is a Baker’s Dozen 13?](/story/why-is-a-bakers-dozen-13)

[![The Battle of New Orleans, by E. Percy Moran, c. 1910. Andrew Jackson, War of 1812.](https://cdn.britannica.com/94/159994-131-8E828D22/Battle-of-New-Orleans-oil-painting-E-1910.jpg?w=200&h=200&c=crop)](/story/25-decade-defining-events-in-us-history)

[26 Decade-Defining Events in U.S. History](/story/25-decade-defining-events-in-us-history)

[![Aphrodite. Greek mythology. Sculpture. Aphrodite is the Greek goddess of love and beauty.](https://cdn.britannica.com/23/176123-131-94DCF6F8/Aphrodite.jpg?w=200&h=200&c=crop)](/list/12-greek-gods-and-goddesses)

[12 Greek Gods and Goddesses](/list/12-greek-gods-and-goddesses)

[![President Kennedy address on Test Ban Treaty, White House, Oval Office, July 26, 1963. President John F. Kennedy, President Kennedy](https://cdn.britannica.com/46/146446-131-83C57663/John-F-Kennedy-Test-Ban-Treaty-Oval-July-26-1963.jpg?w=200&h=200&c=crop)](/list/11-memorable-quotes-from-us-presidential-debates)

[11 Memorable Quotes from U.S. Presidential Debates](/list/11-memorable-quotes-from-us-presidential-debates)

[![Ice Sledge Hockey, Hockey Canada Cup, USA (left) vs Canada,  2009. UBC Thunderbird Arena, Vancouver, BC, competition site for Olympic ice hockey and Paralympic ice sledge hockey. Vancouver 2010 Olympic and Paralympic Winter Games, Vancouver Olympics](https://cdn.britannica.com/13/134913-131-D9520745/Ice-Sledge-Hockey-Canada-Cup-USA-ice-2010.jpg?w=200&h=200&c=crop)](/list/10-best-hockey-players-of-all-time)

[10 Best Hockey Players of All Time](/list/10-best-hockey-players-of-all-time)

[![A group of diverse individuals, who represent various occupations, stand with their arms raised in the air. labor day; laborers; construction worker; teacher; nurse; doctor; assistant; office staff; blue collar; workforce](https://cdn.britannica.com/40/239640-131-052DF02A/diverse-group-occupations-workforce.jpg?w=200&h=200&c=crop)](/story/why-is-labor-day-celebrated-in-september)

[Why Is Labor Day Celebrated in September?](/story/why-is-labor-day-celebrated-in-september)


Contents


[Politics, Law & Government](/browse/Politics-Law-Government)[International Relations](/browse/International-Relations)

# Axis powers

World War II coalition



Actions




Cite


_verified_ Cite


While every effort has been made to follow citation style rules, there may be some discrepancies.
Please refer to the appropriate style manual or other sources if you have any questions.


Select Citation Style

MLAAPAChicago Manual of Style

Copy Citation



Share



Share


Share to social media

[Facebook](https://www.facebook.com/BRITANNICA/) [X](https://x.com/britannica)

URL

[https://www.britannica.com/topic/Axis-Powers](https://www.britannica.com/topic/Axis-Powers)


Give Feedback



External Websites


Feedback


Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).


Feedback TypeSelect a type (Required)Factual CorrectionSpelling/Grammar CorrectionLink CorrectionAdditional InformationOther

Your FeedbackSubmit Feedback

Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

External Websites


- [Khan Academy - 1940 - Axis gains momentum in World War II](https://www.khanacademy.org/humanities/us-history/rise-to-world-power/us-wwii/v/1940-axis-gains-momentum-in-world-war-ii)
- [Pressbooks.ccconline.org - PPSC HIS 1120: The World: 1500-Present - Axis Powers](https://pressbooks.ccconline.org/the-world-1500-present/chapter/axis-powers/)
- [Warfare History Network - Axis Powers: The Infamous Tripartite Pact](https://warfarehistorynetwork.com/article/axis-powers-the-infamous-tripartite-pact/)
- [United States Holocaust Memorial Museum - Holocaust Encyclopedia - Axis Powers in World War II](https://encyclopedia.ushmm.org/content/en/article/axis-powers-in-world-war-ii)

Britannica Websites

Articles from Britannica Encyclopedias for elementary and high school students.

- [Axis Powers - Student Encyclopedia (Ages 11 and up)](https://kids.britannica.com/students/article/Axis-Powers/316790)

[Print](/print/article/46315)


Cite


_verified_ Cite


While every effort has been made to follow citation style rules, there may be some discrepancies.
Please refer to the appropriate style manual or other sources if you have any questions.


Select Citation Style

MLAAPAChicago Manual of Style

Copy Citation



Share



Share


Share to social media

[Facebook](https://www.facebook.com/BRITANNICA/) [X](https://x.com/britannica)

URL

[https://www.britannica.com/topic/Axis-Powers](https://www.britannica.com/topic/Axis-Powers)



Feedback



External Websites


Feedback


Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).


Feedback TypeSelect a type (Required)Factual CorrectionSpelling/Grammar CorrectionLink CorrectionAdditional InformationOther

Your FeedbackSubmit Feedback

Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

External Websites


- [Khan Academy - 1940 - Axis gains momentum in World War II](https://www.khanacademy.org/humanities/us-history/rise-to-world-power/us-wwii/v/1940-axis-gains-momentum-in-world-war-ii)
- [Pressbooks.ccconline.org - PPSC HIS 1120: The World: 1500-Present - Axis Powers](https://pressbooks.ccconline.org/the-world-1500-present/chapter/axis-powers/)
- [Warfare History Network - Axis Powers: The Infamous Tripartite Pact](https://warfarehistorynetwork.com/article/axis-powers-the-infamous-tripartite-pact/)
- [United States Holocaust Memorial Museum - Holocaust Encyclopedia - Axis Powers in World War II](https://encyclopedia.ushmm.org/content/en/article/axis-powers-in-world-war-ii)

Britannica Websites

Articles from Britannica Encyclopedias for elementary and high school students.

- [Axis Powers - Student Encyclopedia (Ages 11 and up)](https://kids.britannica.com/students/article/Axis-Powers/316790)


Written and fact-checked by


[The Editors of Encyclopaedia Britannica\
\
Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. They write new content and verify and edit content received from contributors.](/editor/The-Editors-of-Encyclopaedia-Britannica/4419)

The Editors of Encyclopaedia Britannica

[Article History](https://www.britannica.com/topic/Axis-Powers/additional-info#history)


Table of Contents


[![Axis leaders Adolf Hitler and Benito Mussolini](https://cdn.britannica.com/62/129962-050-C26B63A7/Adolf-Hitler-Benito-Mussolini.jpg?w=400&h=300&c=crop)](https://cdn.britannica.com/62/129962-050-C26B63A7/Adolf-Hitler-Benito-Mussolini.jpg)

Axis leaders Adolf Hitler and Benito Mussolini

[See all media](https://www.britannica.com/topic/Axis-Powers/images-videos)

Date: May 22, 1939 - September 2, 1945_(Show more)_

Related People: [Adolf Hitler](/biography/Adolf-Hitler)[Benito Mussolini](/biography/Benito-Mussolini)[Joachim von Ribbentrop](/biography/Joachim-von-Ribbentrop)_(Show more)_

[See all related content →](/facts/Axis-Powers)

Ask the Chatbot a Question

Ask the Chatbot a Question

**Axis powers**, [coalition](https://www.britannica.com/dictionary/coalition) headed by [Germany](https://www.britannica.com/place/Germany), [Italy](https://www.britannica.com/place/Italy), and [Japan](https://www.britannica.com/place/Japan) that opposed the [Allied powers](https://www.britannica.com/topic/Allied-Powers-international-alliance) in [World War II](https://www.britannica.com/event/World-War-II). The [alliance](https://www.britannica.com/topic/alliance-politics) originated in a series of agreements between Germany and Italy, followed by the proclamation of an “axis” binding [Rome](https://www.britannica.com/place/Rome) and [Berlin](https://www.britannica.com/place/Berlin) (October 25, 1936), with the two powers claiming that the world would henceforth rotate on the Rome-Berlin axis. This was followed by the German-Japanese [Anti-Comintern Pact](https://www.britannica.com/event/Anti-Comintern-Pact) against the [Soviet Union](https://www.britannica.com/place/Soviet-Union) (November 25, 1936).

[![Track the League of Nations' continual failure to check via diplomacy the Axis powers' pre-World War II rise](https://cdn.britannica.com/31/72831-138-0F810906/events-Axis-Powers-world-war.jpg?w=800&h=450&c=crop)](/video/72831/events-Axis-Powers-world-war)

Track the League of Nations' continual failure to check via diplomacy the Axis powers' pre-World War II riseThe 1930s consisted of many individual but significant events that bound the Axis powers and culminated in a World War.(more)

[See all videos for this article](/topic/Axis-Powers/images-videos)

Hostile acts of expansionism by the three countries during the 1930s sowed the seeds of world war. [Fascist](https://www.britannica.com/topic/fascism) Italy invaded [Ethiopia](https://www.britannica.com/place/Ethiopia) on October 3, 1935. Imperial Japan, which had occupied [Manchuria](https://www.britannica.com/place/Manchuria) (Northeast [China](https://www.britannica.com/place/China)) since 1931, engaged Chinese troops near [Beijing](https://www.britannica.com/place/Beijing) on July 7, 1937, thus launching full-scale warfare there. [Nazi](https://www.britannica.com/event/Nazism) Germany occupied the [Rhineland](https://www.britannica.com/place/Rhineland) in 1936 and annexed [Austria](https://www.britannica.com/place/Austria) and the [Sudetenland](https://www.britannica.com/place/Sudetenland) two years later.

[![Germany invades Poland, September 1, 1939, using 45 German divisions and aerial attack. By September 20, only Warsaw held out, but final surrender came on September 29.](https://cdn.britannica.com/26/188426-050-2AF26954/Germany-Poland-September-1-1939.jpg)\
\
Britannica Quiz\
\
Pop Quiz: 17 Things to Know About World War II](/quiz/pop-quiz-17-things-to-know-about-world-war-ii)

On September 13, 1936, as he began to set his sights on the [Soviet Union](https://www.britannica.com/place/Soviet-Union), German dictator [Adolf Hitler](https://www.britannica.com/biography/Adolf-Hitler) boasted of the blind obedience that he would be able to command from the German people in a struggle against [bolshevism](https://www.britannica.com/topic/Bolshevik). Hitler’s tirades against bolshevism were delivered not only in order to justify German intervention on the side of the fascist-oriented [Falange](https://www.britannica.com/topic/Falange) in the [Spanish Civil War](https://www.britannica.com/event/Spanish-Civil-War) (1936–39) but also to prepare the ground for alliance with Japan, where [nationalism](https://www.merriam-webster.com/dictionary/nationalism) and militarism had been ascendant since Japan’s occupation of Manchuria. On November 25, 1936, Germany’s foreign minister, [Joachim von Ribbentrop](https://www.britannica.com/biography/Joachim-von-Ribbentrop), and Japan’s ambassador in Berlin, Count Mushakoji, signed an agreement, the so-called [Anti-Comintern Pact](https://www.britannica.com/event/Anti-Comintern-Pact): since the Comintern, or [Third International](https://www.britannica.com/topic/Third-International), based in [Moscow](https://www.britannica.com/place/Moscow), existed in order “to disintegrate and subdue existing states,” Germany and Japan undertook “to consult with one another on the necessary preventive measures and to carry these through in close collaboration.”

Germany had not enacted any sanctions against Italy during the [Italo-Ethiopian War](https://www.britannica.com/event/Italo-Ethiopian-War-1935-1936) (1935–36): firmly resolved on annexing Austria to Germany, Hitler was waiting until Italy’s war was over before making his next move on the international chessboard. Then, after a bitter campaign in the [Nazi](https://www.britannica.com/topic/Nazi-Party) press against the Austrian chancellor [Kurt von Schuschnigg](https://www.britannica.com/biography/Kurt-von-Schuschnigg), German diplomat [Franz von Papen](https://www.britannica.com/biography/Franz-von-Papen), in May 1936, started negotiations with Schuschnigg for a modus vivendi. A draft agreement between Germany and Austria was submitted to Italian dictator [Benito Mussolini](https://www.britannica.com/biography/Benito-Mussolini), whose approval was obtained on June 5. An official communique published in [Berlin](https://www.britannica.com/place/Berlin) and in [Vienna](https://www.britannica.com/place/Vienna) on July 11 stated that the German [Reich](https://www.britannica.com/place/Third-Reich) recognized Austria’s full [sovereignty](https://www.merriam-webster.com/dictionary/sovereignty) and that Austria undertook, “both in general and toward the German Reich,” to pursue the policy of “a German state.” A visit by Galeazzo Ciano, Mussolini’s son-in-law and minister of foreign affairs, to Hitler at [Berchtesgaden](https://www.britannica.com/place/Berchtesgaden) on October 24 was followed by Germany’s becoming the first power to recognize Italy’s annexation of Ethiopia. On November 1, in [Milan](https://www.britannica.com/place/Milan-Italy), Mussolini completed the bargain by proclaiming the [Rome-Berlin Axis](https://www.britannica.com/topic/Rome-Berlin-Axis) and by violently attacking [communism](https://www.britannica.com/topic/communism).

[![](https://cdn.britannica.com/64/197364-050-F1D668C5/Benito-Mussolini-Italian-Adolf-Hitler-Eastern-Front.jpg?w=300)](https://cdn.britannica.com/64/197364-050-F1D668C5/Benito-Mussolini-Italian-Adolf-Hitler-Eastern-Front.jpg)

[Benito Mussolini with Adolf Hitler](https://cdn.britannica.com/64/197364-050-F1D668C5/Benito-Mussolini-Italian-Adolf-Hitler-Eastern-Front.jpg) Italian dictator Benito Mussolini (left) touring the Eastern Front with German dictator Adolf Hitler (second from right) during World War II. Walking with them are German Nazi leaders Hermann Göring (between Mussolini and Hitler) and Wilhelm Keitel.(more)

In the last week of September 1937, when he paid a state visit to Germany, Mussolini received a spectacular welcome. Convinced that in a forthcoming war the Nazi Reich would be victorious, he formally [subscribed](https://www.britannica.com/dictionary/subscribed) to the German-Japanese Anti-Comintern Pact on November 6 of that year, and on December 11 he withdrew Italy from the [League of Nations](https://www.britannica.com/topic/League-of-Nations). Germany, Italy, and Japan now formed a triangle.

The connections among the Axis powers were strengthened by a full military and political alliance between Germany and Italy (the [Pact of Steel](https://www.britannica.com/event/Pact-of-Steel), May 22, 1939) and by the [Tripartite Pact](https://www.britannica.com/topic/Tripartite-Pact), signed by all three powers on September 27, 1940, one year after Germany’s invasion of [Poland](https://www.britannica.com/place/Poland) and the beginning of World War II. During the war a number of other countries joined the Axis, induced by coercion or promises of territory or protection by the Axis powers. They included [Hungary](https://www.britannica.com/place/Hungary), [Romania](https://www.britannica.com/place/Romania), and [Slovakia](https://www.britannica.com/place/Slovakia) (after [Czechoslovakia](https://www.britannica.com/place/Czechoslovakia) had divided in 1939) in November 1940, [Bulgaria](https://www.britannica.com/place/Bulgaria) and [Yugoslavia](https://www.britannica.com/place/Yugoslavia-former-federated-nation-1929-2003) in March 1941, and, after the wartime breakup of Yugoslavia, [Croatia](https://www.britannica.com/place/Croatia) (June 1941). [Finland](https://www.britannica.com/place/Finland), although it did not formally join the Tripartite Pact, cooperated with the [Axis](https://www.britannica.com/dictionary/Axis) because of its opposition to the Soviet Union (to which Finland had been forced to cede territory in 1940) and entered the war in 1941.

[The Editors of Encyclopaedia Britannica](/editor/The-Editors-of-Encyclopaedia-Britannica/4419)This article was most recently revised and updated by [Michael Ray](/editor/Michael-Ray/6392).