HMS UPHOLDER (Lt Cdr M D Wanklyn) sailed from Malta on 6 April 1942 for a patrol in the Gulf of Tripoli. On 11 April she conducted a rendezvous with HMS UNBEATEN.

Nothing further was heard from UPHOLDER. On 14 April two British submarines patrolling in areas near to UPHOLDER heard prolonged depth-charging and, on the 18 April, the Italians claimed that one of their torpedo boats had sunk a submarine on 14 April.

HMS UPHOLDER was the highest scoring British submarine of World War 2, sinking a total of 133,940 tons of enemy shipping. Lt Cdr Wanklyn had been awarded the Victoria Cross.

UPHOLDER was lost with All Hands.