Which Countries Were Allies of the British in World War II?

When World War II erupted in September 1939, following Nazi Germany’s invasion of Poland, the United Kingdom found itself once again at the center of a vast global conflict. Unlike World War I, this conflict would spread even wider, engulfing nations across Europe, Asia, Africa, and the Pacific. To confront the Axis Powers — mainly Nazi Germany, Fascist Italy, and Imperial Japan — Britain relied heavily on a broad coalition of allies. Together, these countries formed what we commonly call the Allies of World War II.

But who exactly were Britain’s allies, and what roles did they play? Let’s take a deeper look.

The Major Allies

1. The United States of America

Although initially neutral, the United States became a critical ally of Britain. The U.S. began by providing extensive material support through the Lend-Lease Act of 1941, which supplied Britain with food, oil, tanks, planes, and other crucial war materials. After the Japanese attack on Pearl Harbor on December 7, 1941, the United States formally entered the war, declaring war on Japan — and shortly thereafter on Germany and Italy. American industrial might and military manpower dramatically shifted the balance of power. Together with Britain, the U.S. led major campaigns in North Africa, Italy, France, and ultimately Germany itself.

2. The Soviet Union

Initially, the USSR and Nazi Germany were bound by the Molotov-Ribbentrop Pact, a non-aggression treaty. However, that changed abruptly in June 1941 when Hitler launched Operation Barbarossa, invading the Soviet Union. This brutal invasion drove Stalin to join the Allies. The Soviet Union bore the heaviest casualties of the war, fighting massive battles on the Eastern Front like Stalingrad and Kursk, which significantly weakened German forces and diverted Nazi attention from Western Europe.

3. China

China had already been engaged in conflict with Japan since 1937. Following the broader outbreak of World War II, China became recognized as one of the Big Four Allied powers. Under Chiang Kai-shek, China tied down large numbers of Japanese troops in Asia, which prevented Japan from committing even more forces to the Pacific islands or Southeast Asia. This contribution, though often overlooked in Western narratives, was vital to the overall Allied effort.

The British Commonwealth and Dominions

Britain’s greatest initial advantage was the unwavering support from countries across its empire and the Commonwealth.

4. Canada

Canada declared war on Germany just a week after Britain did. Canadian forces fought bravely in key campaigns such as the Battle of the Atlantic, the invasion of Italy, the D-Day landings in Normandy, and the liberation of the Netherlands.

5. Australia

Australia was quick to respond to Britain’s call for support, initially sending troops to fight in Europe and North Africa. However, after Japan entered the war, Australia shifted its focus to defending the Pacific, notably participating in campaigns in New Guinea and the Solomon Islands.

6. New Zealand

New Zealanders served alongside British forces in the Mediterranean, North Africa, and later in the Pacific theatre. They played significant roles in battles like El Alamein and Monte Cassino.

7. South Africa

South African forces fought under British command in East Africa against Italian forces and in North Africa against Rommel’s Afrika Korps.

8. India (then under British rule)

Over two million Indian soldiers served in World War II — the largest volunteer army in history at that time. Indian divisions fought in North Africa, Italy, and famously in the Burma Campaign against the Japanese.

Other European Allies

9. France (Free French)

After France fell to Germany in 1940, Britain supported Charles de Gaulle’s Free French Forces, who continued to fight alongside the British in North Africa, Italy, and eventually during the liberation of France itself.

10. Poland

Although Poland was overrun by Germany and the Soviet Union at the war’s start, many Polish troops escaped to Britain. Polish pilots played a crucial role in the Battle of Britain, and Polish ground forces fought in Italy (notably at Monte Cassino) and during D-Day.

11. Norway, Belgium, Netherlands, and Greece

Governments-in-exile based themselves in London after their countries were occupied by Germany. Many soldiers, sailors, and airmen from these nations fought under British command in various campaigns.

12. Czechoslovakia

Czechoslovakian forces also regrouped in Britain, contributing pilots who flew in the RAF during the Battle of Britain and special operations units that carried out daring sabotage missions.

Other Important Allies

13. Yugoslavia

Though Yugoslavia was invaded and occupied by Axis forces, resistance groups — notably the Partisans led by Josip Broz Tito — tied down large numbers of German troops, indirectly aiding British and Soviet efforts elsewhere.

14. Brazil

In 1942, Brazil joined the Allies and later sent an expeditionary force to fight alongside the British and Americans in Italy.

Why These Alliances Mattered

The sheer geographical spread of these allies made it possible to open multiple fronts against the Axis powers. Britain, an island nation with limited manpower compared to continental giants, depended heavily on its allies to sustain global warfare.

• The United States provided unmatched industrial output and opened a western front in Europe.

• The Soviet Union bled the Nazi war machine dry on the Eastern Front.

• China tied up hundreds of thousands of Japanese troops in Asia.

• The British Commonwealth nations shared the burden across multiple continents.

Together, this coalition overwhelmed the Axis both militarily and economically. No single country could have defeated the Axis powers alone — it took a vast network of cooperation.

Conclusion

World War II was not just a fight for Britain’s survival but a truly global conflict requiring a global alliance. From the jungles of Burma to the beaches of Normandy, from the snows of Russia to the deserts of North Africa, Britain’s allies played indispensable roles in securing victory. Remembering the sacrifices of all these nations underscores how collective effort and solidarity can triumph over tyranny — a lesson that remains vital even today.