Seven days later, on 4 August, Germany invaded Belgium and the United Kingdom entered the war to uphold the Treaty of London (1839).

[4] His first act, the next day, was to request parliamentary approval to increase the strength of the British Army by 500,000 men.

[5] Historian Peter Simkins wrote that Kitchener held the Territorial Force in disdain, calling it an ill-trained "Town Clerk's Army", and this was partially why he set up a parallel recruitment system.

[1][7] The division started to assemble, as a single formation, in April 1915 near Grantham and the first general officer commanding (Major-General William Fry) was appointed on 4 May 1915.

While advance parties left for France the next day, the rest of the formation was reviewed on 4 November by Edward Stanley.

[10] Around this time, a variation of the crest of the Stanley family–an eagle standing above a swaddled infant–was adopted as the divisional insignia.

[9] Following the armistice of 11 November 1918, the division moved back away from the frontline area until it reached the vicinity of Blaringhem, with the HQ based at Renescure, on 4 December.

Towards the end of the month, the formation was tasked with supporting efforts at the army's supply ports at Dunkirk, Calais, Boulogne, and Étaples and relocated to them in January.