Force K was the name given to a Royal Navy task force that was based at Malta. Force K was tasked with disrupting as much as possible the Axis maritime supply routes to North Africa thus weakening the power of Erwin Rommel's Afrika Korps. Up to the creation of Force K in 1941, most of the attacks on Axis shipping in the Mediterranean Sea had been carried out by Royal Navy submarines and RAF aeroplanes. However, these attacks were never decisive as they simply could not destroy the number of Axis transport ships that was necessary to inflict real damage on Rommel's supply lines.
Winston Churchill was a keen supporter of establishing a surface naval force at Malta to attack the Axis. With his backing, Force K was created. It was made up of two cruisers ('Aurora' and 'Penelope') and two destroyers ('Lance' and 'Lively'). Based at Valetta, Force K came into being on Trafalgar Day 1941. Captain W Agnew commanded it.
In November 1941, Force K sank seven German merchant ships and an escorting destroyer. Three other German destroyers were damaged and a British submarine, 'HMS Upholder', eventually sank one. The implications of this attack were immense. Force K - in one attack - knocked out nearly 50% of Rommel's supply line to North Africa. The Italians temporarily stopped further ventures by its merchant fleet.
Churchill used his considerable power to increase the capability of Force K when he persuaded the c-in-c Mediterranean to add two more light cruisers ('Ajax' and 'Neptune') to the force with two 'K'-class destroyers. Such a force continued to inflict major losses on Axis supply lines, peaking with a destruction rate of 60%. The impact of K Force was clear and British intelligence intercepted Axis messages that clearly stated that the Axis forces in North Africa were seriously short of fuel, to such an extent that German and Italian aircraft could only fly one sortie a day.
However, the success of K Force was blunted in December 1941 when it sailed into a minefield off Tripoli. The cruiser 'Neptune' was sunk as was the destroyer 'Kandahar'. Another cruiser, 'Aurora', was badly damaged. The Axis convoy got through and Rommel had sufficient fuel supplies to start his campaign to retake Cyrenaica. Following this only 'HMS Penelope' remained. However, she suffered so much damage in aerial raids while back in Valetta that the crew nicknamed her 'HMS Pepperpot'. 'Penelope' was withdrawn from Malta and Force K was disbanded.