British campaign in the Baltic ( 1918 – 19 ) The British Campaign in the Baltic 1918 – 19 was a part of the Allied intervention in the Russian Civil War . The codename of the Royal Navy campaign was " Operation Red Trek " . The intervention played a key role in enabling the establishment of the independent states of Estonia and Latvia but failed to secure the control of Petrograd by White Russian forces , which was one of the main goals of the campaign . Context . Launched in the wake of the Russian collapse and revolution of 1917 , the purposes of Operation Red Trek were to stop the rise of Bolshevism , protect Britain ' s interests and to extend the freedom of the seas . The situation in the Baltic states in the aftermath of World War I was chaotic . The Russian Empire had collapsed and Bolshevik Red Army , pro - independence , and pro - German forces were fighting across the region . Riga had been occupied by the German army in 1917 and German Freikorps and Baltic - German Landeswehr units were still active in the area . Estonia had established a national army with the support of Finnish volunteers and were defending against the 7th Red Army ' s attack . Naval forces involved . Soviet forces . The Russian Baltic Fleet was the key naval force available to the Bolsheviks and essential to the protection of Petrograd . The fleet was severely depleted after the First World War and Russian revolution but still formed a significant force . At least one " Gangut " - class battleship , as well as several pre - dreadnought battleship s , cruisers , destroyers and submarines were available . Many of the officer corps were on the White Russian side in the Civil War or had been murdered , but some competent leaders remained . British forces . A Royal Navy squadron was sent under Rear - Admiral Edwyn Alexander - Sinclair . This force consisted of modern C - class cruiser s and V - and W - class destroyer s . In December 1918 , Sinclair sallied into Estonian and Latvian ports , sending in troops and supplies , and promising to attack the Bolsheviks " as far as my guns can reach " . In January 1919 , he was succeeded in command by Rear - Admiral Walter Cowan . Main actions . British forces denied the Bolsheviks the ability to move by sea , Royal Navy ships bombarded the Bolsheviks on land in support of Estonian and Latvian troops , and provided supplies . On the night of 4 December , the cruiser struck a mine while on patrol duties north of Liepāja , and sank with the loss of 11 of her crew . On 26 December , British warships captured the Bolshevik destroyers and , which at the time were shelling the port of Tallinn . Both units were presented to the Estonian Provisional Government and , as " Lennuk " and " Vambola " , formed the nucleus of the Estonian Navy . Forty Bolshevik prisoners of war were executed by the Estonian government on Naissaar in February 1919 despite British protests . The new Commissar of the Baltic Fleet — Fedor Raskolnikov — was captured onboard " Spartak " . He was exchanged on 27 May 1919 for 17 British officers captured by the Soviets and later appointed Commissar of the Caspian Flotilla by Trotsky . In the Baltic , Raskolnikov was replaced by Nikolai Kuzmin . In April 1919 , Latvian President Kārlis Ulmanis was forced to seek refuge on board the " Saratov " under the protection of British ships . In the summer of 1919 , the Royal Navy bottled up the Red fleet in Kronstadt . Several sharp skirmishes were fought near Kotlin Island . In the course of one of this clashes , on 31 May , during a Bolshevik probing action to the west , the battleship scored two hits on the destroyer HMS " Walker " from a distance of , when a flotilla of British destroyers attempted to catch the outgunned Bolshevik destroyer " Azard " . " Walker " , which acted as a lure , suffered some damage and two of her crew were wounded , while the other British destroyers eventually disengaged when they came too close to Bolshevik coastal artillery and minefield s . Admiral Cowan soon realised that Tallinn was not an ideal base of operations and sought a base closer to Kronstadt . On 5 June Cowan and his naval units arrived at the new anchorage at Björkö Sound , which proved ideal for actions against Kronstadt . However , on 9 June the Red fleet ' s destroyers " Gavril " and " Azard " raided the location , and the Royal Navy submarine HMS " L55 " was sunk in the aftermath , apparently after being cornered in a British minefield by the Soviet warships . The action prompted the British to lay obstacles and minefields to protect the anchorage . Cowan also requested that Finland allocate a squadron of ships to provide additional protection for the anchorage as well as to take part in the security and patrol duties in the area . The Finnish Navy complied and sent several gun and torpedo boats as well as motor minesweepers to Björkö . A flotilla of British Coastal Motor Boats under the command of Lieutenant Augustus Agar raided Kronstadt Harbour twice , sinking the cruiser " Oleg " and the depot ship " Pamiat Azova " on June 17 as well as damaging the battleships " Petropavlovsk " and " Andrei Pervozvanny " in August , at the cost of three CMBs in the last attack . The British claim that the motor boats damaged the " Petropavlosk " is dismissed by Soviet records . The first raid was intended to support a significant mutiny at the Krasnaya Gorka fort which was eventually suppressed by the guns of the Bolshevik battleships . In early July the British received reinforcements which included the aircraft carrier HMS " Vindictive " whose aircraft carried out bombing and strafing runs against gun and searchlight installations at Kronstadt . In the autumn of 1919 , British forces — including the monitor — provided gunfire support to General Nikolai Yudenich ' s White Russian Northwestern army in its offensive against Petrograd . The Russians tried to disrupt these bombardments by laying mines using the s , " Azard " , " Gavril " , " Konstantin " and " Svoboda " . The latter three ships were sunk in a British minefield on 21 October 1919 , during an attempt to defect to Estonia . The White army ' s offensive failed to capture Petrograd and on 2 February 1920 , the Republic of Estonia and Bolshevist Russia signed the Peace Treaty of Tartu which recognised Estonian independence . This resulted in the withdrawal of the Royal Navy from the Baltic . The prolonged British presence at Björkö Sound and Cowan ' s demands to the Finnish government that the small Finnish squadron patrolling the area stay until the British withdrawal from the sound in December 1919 cost Finnish Navy three torpedoboats which sank when ice crushed their weak hulls . The loss of the three vessels meant that the newly independent Finland ' s small navy lost 20 % of the heavier ships in a single stroke . Significant unrest took place among British sailors in the Baltic . This included small - scale mutinies amongst the crews of , — the latter due in part to the behaviour of Admiral Cowan — and other ships stationed in Björkö Sound . The causes were a general war weariness ( many of the crews had fought in World War I ) , poor food and accommodation , a lack of leave and the effects of Bolshevik propaganda . Ships sunk . British . RN ships lost in the Baltic include : The 112 deaths of British servicemen — 107 RN personnel and five RAF personnel — are commemorated on a memorial plaque , which was unveiled in 2005 at Portsmouth Cathedral in England , with similar memorials in churches in Tallinn and Riga . Soviet . No figures for Soviet casualties are available .