3 September

At 11am on 3 September 1939, the United Kingdom and Germany entered into a state of war because Adolf Hitler's government did not withdraw his troops from Poland. (PROSE: Timewyrm: Exodus)

In 1939, Cecelia "Sissy" Pollard, a member of the League of English Fascists and the younger sister of the Eighth Doctor's companion Charley Pollard, committed suicide in Munich as she was extremely distraught at the idea of the two countries which she loved, Britain and Germany, being at war. (AUDIO: A Blind Eye)

In the 1978 of one version of history, the British Imperial Spacefleet left Earth for the Moon. (PROSE:  Imperial Moon)