"Superb" took part in a test mobilisation and fleet review between 17 and 20 July 1914 as part of the British response to the July Crisis. Arriving in Portland on 27 July, she was ordered to proceed with the rest of the Home Fleet to Scapa Flow two days later to safeguard the fleet from a possible German surprise attack. Captain Price Lewes relived Hope on 28 July. In August, following the outbreak of World War I, the Home Fleet was reorganised as the Grand Fleet, and placed under the command of Admiral John Jellicoe. Most of it was briefly based (22 October to 3 November) at Lough Swilly, Ireland, while the defences at Scapa were strengthened. Lewes was relieved on 4 November for reasons of ill-health and died five days later from a kidney disease. Captain Rudolf Bentinck assumed command of the ship on the 6th. On the evening of 22 November, the Grand Fleet conducted a fruitless sweep in the southern half of the North Sea, during which "Superb" stood with the main body in support of Vice-Admiral David Beatty's 1st Battlecruiser Squadron. The fleet was back in port in Scapa Flow by 27 November. The 1st BS cruised north-west of the Shetland Islands and conducted gunnery practice on 8–12 December. Four days later, the Grand Fleet sortied during the German raid on Scarborough, Hartlepool and Whitby, but failed to make contact with the High Seas Fleet. "Superb" and the rest of the Grand Fleet conducted another sweep of the North Sea on 25–27 December.