Sinking of HMS Cassandra

On 4 December 1918 a British squadron under Rear-Admiral Edwyn Alexander-Sinclair sailed north from Libau in Latvia: according to Estonian accounts, four light cruisers and nine destroyers. It was bound for Tallinn, the capital of Estonia, against which the Red Army had been advancing for a week. During the night of 4–5 December, in the open sea west of the island of Saaremaa, the cruiser Cassandra struck a mine from a German barrage laid during the war and not marked on British charts. A British chronology of the war records the sinking under 4 December, with the note “night of 4th/5th”, while some accounts give 5 December.

A squadron in the Baltic

After the Armistice of Compiègne the Baltic lay open to the surface ships of the Royal Navy, which had been unable to get there during the war. German troops were withdrawing from the Baltic countries, and the Bolsheviks were moving in to take their place. The British government, which in November had confirmed its recognition of the Latvian National Council and had earlier declared its readiness to recognise the Estonian provincial assembly, decided to send ships to the Baltic. They were to show the flag in the ports of the new states, bring them weapons and hold the Bolshevik fleet in check. The task went to the 6th Light Cruiser Squadron of the Grand Fleet. Its flagship, Cardiff, had a few days earlier led the German High Seas Fleet into internment. With the squadron sailed two minelayers carrying rifles and ammunition for the Estonians and Latvians.

According to Estonian accounts, the ships left Britain at the end of November, sailing via Copenhagen, where Alexander-Sinclair met representatives of Estonia, and on 1 December anchored at Libau. The minesweepers stayed behind in Copenhagen, because they were unfit for service in the Baltic, and the British had no accurate charts of the minefields with which the Germans and Russians had strewn the eastern Baltic during the war.

The explosion

Cassandra was a new ship: she had been launched at the Vickers yard in Barrow in November 1916 and commissioned in June 1917. She carried five 6-inch (152 mm) guns and a crew of about 400. The mine exploded beneath the engine room. The blast killed ten men of the engine-room crew, stokers and mechanics, as confirmed by the Royal Navy’s roll of the fallen. The ship came to a stop and began to take on water. The destroyers Westminster and Vendetta came alongside. According to Estonian sources, Westminster managed to take off a dozen or so men before the heavy sea forced her away, and Vendetta took off the rest of the crew. During the evacuation one sailor fell into the sea and drowned. In all, therefore, eleven men were killed. The cruiser went down within about an hour.

The position of the wreck long remained uncertain. The Royal Navy’s roll of the fallen places the sinking in the Gulf of Finland, and some accounts north of Libau. The wreck was found only in August 2010, by sonar, by the Estonian minehunter Ugandi, in deep water near Saaremaa. It lies on its starboard side, with part of the bow missing.

The squadron’s later fortunes

Bad luck dogged the British in the following days as well. According to Estonian accounts, on 6 December the destroyers Verulam and Westminster collided in fog. At the Admiralty there was even talk of recalling the squadron, but in the end it was left in the Baltic. It reached Tallinn a few days later, guided through the minefield by Estonian pilots whom Colonel Johan Laidoner had brought to Libau. The British cruisers later shelled the coast held by the Reds, and the weapons delivered helped the Estonians in their counter-offensive in January 1919. Cassandra was the first ship the Royal Navy lost during its operations in the Baltic in 1918–1919.