HMS Amphion was an Active-class scout cruiser built for the Royal Navy before the First World War. Completed in 1913, she was initially assigned to the First Fleet and became a destroyer flotilla leader in mid-1914. When the war began, her flotilla was assigned to the Harwich Force. While patrolling on the first full day of the war, Amphion and her destroyers encountered and sank a German minelayer, SMS Königin Luise, but not before she had laid many of her mines. While returning from patrolling the following morning, Amphion struck a mine on 6 August 1914 off the Thames Estuary and sank with the loss of 132 crewmen killed. She was the first ship of the Royal Navy to be sunk in the First World War. The wreck site is protected and may not be dived upon without permission from the Ministry