As the military governor of Paris, von Choltitz received direct orders from Hitler to destroy the city — "Is Paris burning?" Hitler demanded. Von Choltitz later claimed he disobeyed because he believed Hitler was insane and the destruction would serve no military purpose.

Source: Larry Collins & Dominique Lapierre, Is Paris Burning?

While Enigma is famous, the Lorenz cipher was used for the highest-level German communications, including messages between Hitler and his generals. Breaking it led to the creation of Colossus — the world's first programmable electronic computer.

Source: Jack Copeland, Colossus: The Secrets of Bletchley Park

He was a Welsh vagrant who died from ingesting rat poison in a London warehouse. His identity was classified until 1996. He is buried in Huelva, Spain, under the name "Major William Martin, RM."

Source: Ben Macintyre, Operation Mincemeat

The 442nd Regimental Combat Team, composed almost entirely of Japanese Americans (Nisei), became the most decorated unit of its size in U.S. military history, earning over 18,000 individual decorations — including 21 Medals of Honor — while many of their families were imprisoned behind barbed wire.

Source: Masayo Umezawa Duus, Unlikely Liberators

The French Resistance launched an uprising on August 19, 1944, and largely controlled the city by the time the Free French 2nd Armored Division arrived on August 25. De Gaulle insisted that French forces enter Paris first.

Source: Antony Beevor, D-Day: The Battle for Normandy