The First Allies shot of the first world war was fired from the Port Phillip batteries. The German ship SS Pfalz was trying to flee Port Phillip after it had been informed of the outbreak of war.
The fire commander at Fort Nepean, Lieutenant C Morris, was givent he order to stop or sink the SS Pfalz as she tried to escape. The Germans ignored signals to halt and the B1 gun (pictured below) fired across her bow.
After the warning shot the Germans turned around and were arrested at Portsea.