80 Years Ago—September 17, 1939: Soviet troops (allied with Germany) invade Poland, surrounding Polish troops.
150 Polish military and civilian planes fly to Romania; pilots will make way to Britain to fight again.
Off the Irish coast, U-boat U-29 sinks British aircraft carrier HMS Courageous, 518 killed.
75 Years Ago—Sept. 17, 1944: Operation Market Garden begins: 20,000 US and British paratroopers land in Nijmegen, Eindhoven, and Arnhem in the Netherlands, with a British ground offensive designed to link with the airborne units.
In Italy, US Fifth Army breaks the German Gothic Line at Il Giogo Pass.