World War II: France, the United Kingdom, New Zealand and Australia declare war on Germany after the invasion of Poland, forming the Allies.

The Allies begin their attack on the Norwegian town of Narvik which is occupied by Nazi Germany.

World War II: The Battle of Dunkirk ends with a German victory and with Allied forces in full retreat.

World War II: Operation Ariel begins – Allied troops start to evacuate France, following Germany's takeover of Paris and most of the nation.

World War II: President Franklin D. Roosevelt signs the Lend-Lease Act into law, allowing American-built war supplies to be shipped to the Allies on loan.

World War II: The German submarine ''U-110'' is captured by the Royal Navy. On board is the latest Enigma cryptography machine which Allied cryptographers later use to break coded German messages.

World War II: Allies invade Syria and Lebanon.

World War II: Franklin Delano Roosevelt approves U.S. $1 billion in Lend-Lease aid to the Allied nations.

Mexico enters World War II on the side of the Allies.

World War II: second day of the Battle of the Eastern Solomons. A Japanese naval transport convoy headed towards Guadalcanal is turned-back by an Allied air attack, losing one destroyer and one transport sunk, and one light cruiser heavily damaged.

World War II: Japanese ships retreat after their defeat in the Battle of Cape Esperance with the Japanese commander, Aritomo Gotō dying from wounds suffered in the battle and two Japanese destroyers sunk by Allied air attack.

World War II: Germany invades Vichy France following French Admiral François Darlan's agreement to an armistice with the Allies in North Africa.

World War II: The Battle of Guadalcanal ends in a decisive Allied victory.

Imperial Japanese naval forces complete the evacuation of Imperial Japanese Army troops from Guadalcanal during Operation Ke, ending Japanese attempts to retake the island from Allied forces in the Guadalcanal Campaign.

World War II: Allied authorities declare Guadalcanal secure after Imperial Japan evacuates its remaining forces from the island, ending the Battle of Guadalcanal.

World War II: General Dwight Eisenhower is selected to command the allied armies in Europe.

World War II: The discovery of a mass grave of Polish prisoners of war executed by Soviet forces in the Katyń Forest Massacre is announced, alienating the Western Allies, the Polish government in exile in London, from the Soviet Union.

World War II: German Afrika Korps and Italian troops in North Africa surrender to Allied forces.

World War II: An Allied invasion fleet sails for Sicily (Operation Husky, July 10, 1943).

World War II: The U.S. Seventh Army under General George S. Patton arrives in Messina, Italy, followed several hours later by the British 8th Army under Field Marshal Bernard L. Montgomery, thus completing the Allied conquest of Sicily.

World War II: United States General Dwight D. Eisenhower publicly announces the Allied armistice with Italy.

World War II: The Allies land at Salerno and Taranto, Italy.

World War II: Naples falls to Allied soldiers.

World War II: The new government of Italy sides with the Allies and declares war on Germany.

World War II: The Allies commence Operation Shingle, an assault on Anzio, Italy.

World War II: Operation Persecution is initiated – Allied forces land in the Hollandia (currently known as Jayapura) area of New Guinea.

World War II: The Allies begin a major offensive against the Axis Powers on the Gustav Line.

World War II: Battle of Normandy begins. D-Day, code named ''Operation Overlord'', commences with the landing of 155,000 Allied troops on the beaches of Normandy in France. The allied soldiers quickly break through the Atlantic Wall and push inland in the largest amphibious military operation in history.

World War II King Michael of Romania dismisses the pro-Nazi government of General Antonescu, who is arrested. Romania switches sides from the Axis to the Allies.

World War II: Paris is liberated by the Allies.

World War II: The first Allied troops of the U.S. Army cross the western border of Germany.

World War II: Maastricht becomes the first Dutch city to be liberated by allied forces.

World War II: Allied Airborne troops parachute into the Netherlands as the "Market" half of Operation Market Garden.

Dueren, Germany is destroyed by Allied bombers.

World War II: The German ''Luftwaffe'' launches ''Unternehmen Bodenplatte'', a massive, but failed attempt to knock out Allied air power in northern Europe in a single blow.

World War II: Hungary agrees to an armistice with the Allies.

World War II: The German Army in Italy unconditionally surrenders to the Allies.

World War II: Axis Sally delivers her last propaganda broadcast to Allied troops.

World War II: Heinrich Himmler, the head of the SS, commits suicide while in Allied custody.

World War II: the leaders of the three Allied nations, Prime Minister of the United Kingdom Winston Churchill, President of the United States Harry S Truman and Soviet Premier Joseph Stalin, meet in the German city of Potsdam to decide the future of a defeated Germany.