Seventeen people went on trial in the second Moscow Trials.
Many were sent to death for their crimes in the Great Purge.
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The Moscow Metro was opened to the public.
Adolf Hitler's German military attacked Moscow.
Moscow was mentioned for the very first time in historical records when two princes met there for a great banquet.
The 14th IAAF World Championships opened in Moscow, Russia.
Chemical elements Moscovium, Tennessine, and Oganesson were added to the Periodic Table of Elements.