The raid followed a similar one carried out by a single motor torpedo boat outside the harbour on 17 June 1919, in which Lieutenant Augustus Agar's CMB-4 sank the Bolshevik cruiser Oleg.

The raid on 18 August 1919 was carried out by a newly arrived force of seven larger CMBs under Commander Claude Congreve Dobson, guided by Agar in CMB-4.

One CMB broke down en route to the harbour but the remaining six penetrated the defences and scored hits on the submarine depot ship Pamiat Azova, which sank, and the battleship Andrei Pervozvanny, which was damaged.

The British campaign in the Baltic began on 26 November 1918, just 15 days after the end of the First World War, when a squadron under Rear Admiral Edwyn Alexander-Sinclair departed Britain.

Alexander-Sinclair's force was meant as a show of strength against the Bolsheviks and in support of Estonian and Latvian independence, which was threatened following the withdrawal of German garrisons.

[1]: 12  In spring 1919 the Bolshevik Baltic fleet sortied and, though the conflict was inconclusive, it spurred Cowan to look for a forward base for his ships.

[2][1]: 14–16  Cowan received reinforcements in early June in the form of two 40 ft (12 m) coastal motor boats (CMBs) - CMB-4 and CMB-7 - under the overall command of Lieutenant Augustus Agar.

[1]: 14–16  These were small, fast - capable of 25 knots (46 km/h; 29 mph) - and lightly armed vessels; each carried a machine gun and one British 18-inch torpedo.

[1]: 14–16, 46  Agar's instructions were to establish a ferry service for information and agents from Terijoki in Finland into Bolshevik-controlled territory, including Kronstadt.

[1]: 17  Oleg sank and Agar successfully returned to base, winning the Victoria Cross for his actions and a £5,000 bounty on his head from the Bolsheviks.

Donald carried out two air raids on Kronstadt on 30 July but heavy anti-aircraft fire was reported and no damage was inflicted.

[3] During the next few weeks Cowan carried out bombardments of Ingermanland and patrolled Koporye Bay and Seiskari Island in case the Baltic Fleet put to sea.

The submarine depot ship Pamiat Azova was moored directly opposite the entrance and was hit amidships by a torpedo fired by CMB-79, sinking her.

[1]: 19 The distraction caused by the first wave allowed CMB-31 and CMB-88 to escape to open sea, covered by Agar in CMB-4, who launched his torpedo into the harbour entrance to deter any pursuit.

[1]: 19  Between seven and ten men were killed in the action (the Commonwealth War Graves Commission lists eight Royal Navy dead: three each from CMB-79 and CMB-62, plus Brade and Dayrell-Reed).

[8][3] Dobson rose to eventually become a rear admiral, he donated a safety pin from one of the torpedoes fired from CMB-31 to the collection of the Imperial War Museum.

[1]: 20  The raid served to galvanise the sailors of the Baltic Fleet in their support of the Bolsheviks, as it united disparate factions against a foreign enemy.

An attempt in late October to bombard Krasnaya Gorka by a monitor, Erebus, failed due to lack of ammunition and the loss of her spotting aircraft.

[1]: 22 In November Cowan's ships drove back attacks on Riga and Libau (modern-day Liepāja) by the German-supported West Russian Volunteer Army.