Which event marked a turning point for the Allies during World War II?

The Battle of El Alamein marked a significant turning point for the Allies during World War II primarily due to its strategic implications in the North African theater. Fought in late 1942, this battle saw British forces successfully halt the advance of Axis troops, particularly the Afrika Korps led by General Erwin Rommel. The victory at El Alamein not only boosted Allied morale but also marked the beginning of a series of offensives that would eventually lead to the retreat of Axis forces from North Africa.

This battle demonstrated the effectiveness of coordinated Allied tactics and logistics, signaling a shift in the momentum of the war. It effectively put the Allies on the offensive, laying the groundwork for subsequent campaigns in Europe and the liberation of Axis-occupied territories.

Other events like the signing of the Treaty of Versailles are historically significant but relate more to the post-World War I context rather than a specific turning point in World War II. The Battle of Britain was crucial for preventing a German invasion of the UK but did not directly lead to a shift in the war's trajectory. The invasion of Poland marked the start of World War II rather than a turning point for the Allies within the conflict itself.