In April 1903, Ingouville-Williams was transferred from the East Kents to the Worcestershire Regiment as a major.[6] The next year he took command of the 2nd Battalion of the Worcesters, with whom he spent much of the following five years in British India, during which time he was promoted twice, first to lieutenant colonel in March 1904[7] and then to brevet colonel in December 1905.[8] After completing his tour as his battalion's commanding officer (CO), he was, after being promoted to the full rank of colonel in March 1908,[9] placed on a period of half-pay.[10]
Ingouville-Williams and his brigade, now part of the 6th Division, were ordered to France soon after the outbreak of the First World War.
He remained in command of the 16th Brigade until June 1915, when he was promoted to major-general[14] and sent home to command the newly formed 34th Division, a Kitchener's Army unit. After training in England, he took the 34th to the Western Front in January 1916 and led the division at the beginning of the Battle of the Somme in summer 1916. He earned another four mentions in despatches during the war. On 22 July, Ingouville-Williams and his aide-de-camp personally inspected the ground on which the division was expected to fight the following week. On his way back, he was caught in an artillery barrage and was killed instantly after being struck by a piece of shrapnel.