The city of Melbourne sits at the head of Port Philip Bay, one of the largest natural bays in the world.
(map from Wikipedia)
This huge body of water narrows down to a channel about 3 kilmometres across at its southern end. Defences for Victoria were natually concentrated here during the colonial days. Fort Nepean was constructed at the tip of the Mornington Peninsula, with Fort Queenscliff on the western side.
Historians professional and amateur are still arguing over the moment at which World War 1 was officially opened. There is broad agreement that Australia’s first shots were fired from Fort Nepean; some authorities say these were the first shots fired by any of the Allied armies. Britain declared war on Germany on the evening of August 4 1914; here on the far side of the world, the German ship Pfalz was sailing down the bay. News of the declaration reached Fort Queenscliff. The Pfalz ignored signals calling on it to halt.
The soldiers and sailors stationed at Fort Nepean in Port Melbourne received their orders just as the German ship approached a line of fire which threatened to expose the suburb of Queenscliff to any stray shells.
With moments to spare, at 12.39pm, the gunners opened fire. The six-inch gun hurled its 45kg shell at the steamer. A geyser of water went right over the ship. A pilot boat rushed alongside: Pull up, or the next shot will be aimed right at you, came the shouted warning.
The shot was fired by Sergeant John Purdue.
Purdue remained in the army and rose to the rank of colonel.
‘Verdammt, scherzen sie nicht,’ muttered the captain of the Pfalz – or words to that effect. He turned the ship around and surrendered.
The Pfalz did see wartime service in due course. Australia used it as a troop ship.
Fort Nepean has been preserved as a historical site. As has Fort Queenscliff.
The guns of Port Philip were fired only twice in anger. Once at the start of WW1, and again at the declaration of WW2. The circumstances were less historic in 1939. Nepean again fired across the bows of a ship entering Bass Strait, but it was only an Australian freighter that had failed to identify itself.