Attack on Sydney Harbour
From 31 May to 8 June 1942, during World War II, Imperial Japanese Navy submarines made a series of attacks on the Australian cities of Sydney and Newcastle. On the night of 31 May – 1 June, three Ko-hyoteki-class midget submarines (M-14, M-21 and M-24), each with a two-member crew, entered Sydney Harbour, avoided the partially constructed Sydney Harbour anti-submarine boom net, and attempted to sink Allied warships.