HMS Unison (P43) was a Royal Navy U-class submarine built by Vickers-Armstrong at Barrow-in-Furness, and part of the third group of that class.

On 2 August 1943 Unison was fired on in error by the American tanker Yankee Arrow off Cape Bon, causing damage to her pressure hull, although she was able to return to dock at Bizerte under her own power.

The attack killed the officer of the watch, and severely injured three other crew members, including her captain, Lieutenant Anthony Daniell DSO DSC.

During War Week, March 1942, HMS Unison was adopted by the people of Ashby-de-la-Zouch.

These plaques were recently discovered, reunited and presented to Ashby de la Zouch museum to be put on display.