Over the course of 1917 the Admiralty became more concerned about German efforts in the North Sea to sweep paths through the British-laid minefields intended to restrict the actions of the High Seas Fleet and German submarines. A preliminary raid on German minesweeping forces on 31 October by light forces destroyed ten small ships and the Admiralty decided on a larger operation to destroy the minesweepers and their escorting light cruisers. Based on intelligence reports the Admiralty decided on 17 November 1917 to allocate two light cruiser squadrons, the 1st Cruiser Squadron covered by the reinforced 1st BCS (less "Renown") and, more distantly, the battleships of the 1st Battle Squadron to the operation.