The HM Submarine L55 memorial dates from 1928 when the remains of the crew were repatriated after almost a decade, following the raising of the sunken vessel the previous year.
The L55 was a British L-Class submarine, built on the Clyde, that had been in service for only a year before being sunk during the Allied intervention into the Russian Civil War. On 4 June 1919 the submarine unsuccessfully attacked two Bolshevik destroyers that were laying mines to protect Petrograd (now St Petersburg) and in so doing suffered damage and was sunk. Although the Bolsheviks claimed responsibility for sinking the vessel there is some doubt, as it sunk in an area heavily laid with British mines.
In 1927 the L55 was raised by the Russians; their policy not to allow British war ships within their waters was upheld, and the remains of the crew were collected by a British merchant ship before being transferred to HMS Champion to make the journey home. 32 coffins were buried in a communal grave on 7 September 1928.
The submarine went on to have a chequered career under Russian control, sinking for a second time, along with 50 men, in 1931. She became a training craft, but was damaged in 1941 and was finally broken up in 1953.
From Historic England