August 1: British submarine HMS Spearfish (69S) is sunk.

August 3: The Lithuanian SSR, Latvian SSR (August 5) and Estonian SSR (August 6) are incorporated into the Soviet Union six weeks after their anaxation.

August 4: Gen. John J. Pershing, in a nationwide radio broadcast, urges all-out aid to Britain in order to defend the Americas, while Charles Lindbergh speaks to an isolationist rally at Soldier Field in Chicago.

August 8: Wilhelm Keitel signs the "Aufbau Ost" directive, which eventually leads to the invasion of the Soviet Union.

August 10: British armed merchant cruiser HMS Transylvania (F56) is torpedoed off Malin Head, Ireland, by German submarine U-56.

August 18: HRH The Prince Edward, Duke of Windsor, is installed as Governor of the Bahamas.

August 20: Winston Churchill pays tribute in the House of Commons of the United Kingdom to the Royal Air Force: "Never in the field of human conflict was so much owed by so many to so few." - Leon Trotsky is attacked with an ice axe in his Mexico home by NKVD agent Ramón Mercader.

August 21: Leon Trotsky dies of injuries sustained.

August 24: Howard Florey and a team including Ernst Chain and Norman Heatley at the Sir William Dunn School of Pathology, University of Oxford, publish their laboratory results showing the in vivo bactericidal action of penicillin. They have also purified the drug.

August 26: Chad is the first French colony to proclaim its support for the Allies.

August 30: Second Vienna Award: Germany and Italy compel Romania to cede half of Transylvania to Hungary. (source: Wikipedia)