As battles raged across Russia, North Africa and the Pacific, and German and Allied airplanes dropped bombs on civilians in towns and cities, the Allies began to get the upper hand.
In Europe, the Allies were victorious in North Africa and invaded Italy, which promptly changed sides and joined the Allies. The Germans stayed in Italy and continued to fight.
In 1944, the Allies invaded the beaches of Normandy in Northern France on D-Day, and progressed towards Germany. The Russians reached Berlin, and Hitler committed suicide. Germany surrendered. Allied troops were shocked to find concentration camps in Germany where millions of Jewish people had been murdered.
War continued in the Far East, until the Americans dropped atomic bombs on Hiroshima and Nagasaki, causing the Japanese to surrender. Over 60 million military and civilians across the world were killed in World War 2, including 449,000 British casualties.