At the outbreak of the World War I in August 1914, "Lord Nelson" became flagship of the Channel Fleet and was based at Portland. With other ships, she covered the safe transport of the British Expeditionary Force, under the command of Sir John French, to France. On 14 November, she transferred to Sheerness to guard the English coast against the possibility of a German invasion. The ship returned to Portland Harbour on 30 December and patrolled the English Channel until February 1915.