May–August 1939

Prelude to Madness. In the years immediately preceding World War II, much of the world is in turmoil. From South America to Spain, unrest, internal turbulence, even clashes between countries, is the order of the day. Two countries, in particular—Japan and Germany—show signs of increasing aggression. Having already invaded Manchuria, the Japanese pursue a policy of expansion into China. Meanwhile, to the west, Germany invades Austria, and then occupies Czechoslovakia. By the fall of 1939, the stage is set for the onset of World War II—Germany’s invasion of Poland.

 

September 1939

1
Germany invades Poland, setting stage for World War II.

3
Battle of the Atlantic begins as German U-boat sinks British liner Athenia.

17
Soviet Union invades Poland.

27
Britain suffers major naval loss when aircraft carrier Courageous is sunk.

 

October 1939

14
German submarine sinks the Royal Oak. Depending on 60 million tons of imports a year, British shipping is particularly vulnerable to attacks by German U-boats in the early days of the Battle of the Atlantic. In a daring raid, U-47 Lt. Cmdr. Guenther Prien takes his submarine into Scotland’s Orkney Islands toward Scapa Flow, where the British Home Fleet is based. Unleashing his torpedoes, Prien sinks the battleship Royal Oak, with a loss of more than 800 officers and men.

 

November 1939

30
Soviet Union invades Finland. Fearing a German invasion, the USSR seeks to occupy port and mainland bases in the Baltic states. When Finland denies access to the Soviets, armies totaling nearly a million invade from the southeast. Expecting to achieve victory within two weeks, the Red Army grossly underestimates the fierce winter temperatures and Finnish survival capabilities and suffers 300,000 fatalities. Finland’s defeat is not secured until March 1, 1940.