The commander of the force was Commodore David Norris, who planned an attack against the key Soviet Russian naval base in the Caspian Sea.

[1] Despite the presence of two small submarines and a destroyer on the Soviet side, superior numbers of auxiliary cruisers gave the British ships an advantage.

Still, Norris's ships could enjoy superior numbers: on May 21, the flotilla approached Alexandrovsky Fort and the Soviets lost the patrol boat Schastlivyy due to grounding while attempting to distract the British.

The depot-ship Revel was full of oil and a large explosion was triggered after she was hit, mortally damaging the minelayer Demosthenes (later scuttled).

The Soviet flagship Caspian, despite being damaged, was fit enough to lead the evacuation of the garrison: Kruger and Ventured attempted to intercept the convoy but the sudden arrival of the destroyers Karl Liebknecht and Yakov Sverdlov resulted in a brief stand-off and the British ships retreated.