Following the outbreak of World War I in August 1914, the squadron conducted operations in the English Channel, and was based at Sheerness to guard against a possible German invasion. In the first days of the war, the 5th Battle Squadron covered the crossing of the British Expeditionary Force to France. On 31 December, the squadron was conducting training exercises in the English Channel, and despite the risk of German submarines, was without anti-submarine protection; the German stalked the ships during the day and in the early hours of 1 January 1915, torpedoed "Formidable" twice, sinking her with very heavy loss of life.