Two years after proposing a Jewish state, Great Britain issues a "White Paper" that severely limits Jewish immigration to Palestine. The move is meant to win Arab support for the expected war with Germany.
Violating the Munich Agreement, Hitler occupies portions of Czechoslovakia.
Italy invades Albania.

Adolf Hitler and Benito Mussolini in Munich, Germany
Germany and Italy sign the Pact of Steel military alliance.
May-June: The SS St. Louis, a German passenger ship, leaves Germany with about one thousand refugees bound for Cuba, which denies them entry, as does the United States. The St. Louis returns to Europe, where Britain, France, Belgium, and the Netherlands accept the refugees.
Germany and the Soviet Union sign the Nazi-Soviet Non-Aggression Pact.
Germany invades Poland. The Soviet Union also invades Poland. Britain and France declare war on Germany, starting World War II.
The SS establishes Jewish councils to govern Jewish ghettos and to carry out German orders. Faced with a nearly impossible task of satisfying both their Nazi masters and tens of thousands of Jews herded into small areas where they suffer from overcrowding and disease, the councils vary in how they conduct their business.

Two Jewish men wearing yellow stars stand in front of a shuttered store in an unidentified Polish ghetto
The Nazi governor of Poland requires Jews to wear the Star of David on their clothing for identification.
Hitler orders the T4 Euthanasia Program to eliminate those deemed by Nazis to be unworthy of life due to alleged genetic diseases or defects.