World War II: The <a href="https://en.wikipedia.org/wiki/Imperial_Japanese_Navy" id="mwtw" rel="mw:WikiLink" title="Imperial Japanese Navy">Imperial Japanese Navy</a> submarines <a href="https://en.wikipedia.org/wiki/Japanese_submarine_I-21" id="mwuA" rel="mw:WikiLink" title="Japanese submarine I-21">I-21</a> and I-24 shell the Australian cities of Sydney and <a href="https://en.wikipedia.org/wiki/Newcastle,_New_South_Wales" id="mwuQ" rel="mw:WikiLink" title="Newcastle, New South Wales">Newcastle</a>.