The national flag of the United Kingdom combining the Cross of Saint Andrew (representing Scotland) with the Cross of Saint George (representing England) and the Cross of Saint Patrick (representing Northern Ireland), the three parts of the United Kingdom.

England entered World War II after the Germans invaded Poland in September of 1939.

The White Ensign became the sole ensign of the Royal Navy in 1864. Nelson used the White Ensign at Trafalgar; it replaced the traditional Red Ensign.

Merchant ships always use the Red Ensign (a red field with the Union Jack in the canton).

Since the first French Revolution the “tricolores” had been the only official French Flag. However, Northern France, including Paris, fell to Germany in the first 6 months of World War II. In the southern part of France a semi-independent French government survived by negotiating a separate peace treaty with Hilter and established their capital at Vichy, France. The Vichy government survived by supporting Nazi policies and cooperating with the invaders. After the war the supporters of this puppet government were branded traitors by the new French government.

The occupied part of France and those French citizens and fighters who fled the Nazi conquest, mainly to England, were known as the Free French and were led by General Charles de Gaulle. They fought on the allied side and many risked their lives as resistance fighters in France.

Vice Admiral Émile Muselier, two days after assuming the post of Chief of the Naval and Air Forces of the Free French, created this flag displaying the French colors with a red cross of Lorraine, to recall the perseverance of Joan of Arc, whose symbol it had been.

Although this is not technically a World War II flag, this special naval jack is authorized for ships of the French Navy bearing the names of vessels which served in the Free French Navy (FNFL) during World War II. It displays a red Cross of Lorraine, the emblem of Free France, placed on a white diamond resting on a blue and red vertical striped field. I've put it here because it just seemed to fit.

The Russians entered World War II after the Germans attacked in 1940.

It was this ensign that the USSR's navy used during World War II. Soviet naval warships used this ensign between the years 1935 and 1992. With the colapse of the Soviet Union this ensign was replaced by the traditional flag of Russia (consisting of a blue "Cross of Saint Andrews" on a plain white field) first introduced in the time of Peter the Great.

In 1912, two stars were added to the United States flag, representing Arizona and New Mexico, bringing the total number of stars to 48. They were arranged in six rows of eight stars each. American fighting men would fight under this flag during four wars: World War I, World War II, the Korean War, and the beginning of the Vietnam War. (In 1959, a star was added for Alaska, and in 1960, a star was added for Hawaii making 50 stars today)

A jack is a flag that looks like the union or canton of a national flag. For ships of the United States Navy, it is a blue flag containing a star for each state. On warships, the jack is flown from a flag pole (jack-staff) located on the vessel's front end (bow) when at anchor or in port. American fighting ships would display this jack in World War I, World War II, and the Korean War.

The Australian flag is composed of three parts: The Union Jack (British flag) in the top left corner, the "Star of Federation" in the bottom left corner, and the Southern Cross, taking up the right half of the flag.

The Union Jack shows that the first colonization by Europeans was by Britain, at first as a penal colony. The Star of Federation is a seven-pointed star representing each of the six states, and having one more point for Australia's territories. The Southern Cross is a constellation that can be seen from all of Australia's states and territories.

The Australian Red Ensign was for all vessels registered in Australia. Initially, the Red Ensign was also the only flag private citizens could fly on land, but this was changed by the 1953 Flags Act. The Blue Ensign became the only flag private citizens could fly on land, while the use of the Red Ensign on land was prohibited. This is still true today.

The flag shown here was not actually adopted until 1967. Throughout World War II the Royal Australian Navy, along with their Canadian, South African, New Zealand and Indian colleagues still used the British White Ensign (shown above).

The final member of the "Big Four" of the Allies was China, a land racked with the hatred that only an ongoing and bloody Civil War can cause. The years of ruthless fighting between Mao Tse-tung's Chinese Communist Party (CCP) and Chiang Kai-shek's Kuomintang (KMT), as well as the rivalry among regional war lords had left a violent legacy as the parties battled for political control. Even so, the Chinese Nationalist government would prove to be an important ally in the war in the Pacific as they worked with the United States and their allies to defeat Japan in the Pacific. The Allied forces who served in the Chinese campaign never lost sight of their goal to assist the guerrilla forces and the Chinese government struggling to regain their country from the Japanese.

In July of 1853, Commodore Matthew Perry entered Tokyo Bay with a squadron of then modern warships flying this 31-star flag to secure a treaty with Japan. His success led to formal diplomatic ties, access of ports by American ships, aid for shipwrecked American sailors, commercial trade, and the opening of Japan to other Western nations.

This simple red "V" on a navy blue fielded flag was released to celebrate the victory over Japan in 1945, but its manuafacture actually dates back to 1944. Today in the United States the name "VJ Day" (Victory over Japan) is celebrated on August 15, because of a huge two-day worldwide celebration that took place after the Empire of Japan announced it was surrendering in August - thus ending the fighting in World War II. The holiday is also referred to as "Victory in the Pacific," or VP Day, in Australia where it is celebrated each August 16. However, the official formal surrender didn't take place until September 2 in Tokyo Bay. This happened aboard the USS Missouri when the actual surrender papers were signed.

The "Four Freedoms flag" or "United Nations Honor Flag," was influenced by Roosevelt's Four Freedoms speech, and intended to symbolize the World War II Allies and their goals, as set down in the Atlantic Charter and the Declaration by United Nations. This flag was designed by Brooks Harding in October 1942, and saw some use between 1943 and 1948.