World War II: <a href="https://en.wikipedia.org/wiki/Polish_government-in-exile" id="mw8w" rel="mw:WikiLink" title="Polish government-in-exile">Poland</a> declares war on the <a href="https://en.wikipedia.org/wiki/Empire_of_Japan" id="mw9A" rel="mw:WikiLink" title="Empire of Japan">Empire of Japan</a>.