On 23 May 1891 Maxse exchanged into the Coldstream Guards. After short service in Scotland, Ireland and Malta he was selected in 1896 by Colonel Kitchener to serve as a Bembashi (Major) in the Egyptian Army. Shortly afterward, he was given command of the 13th Sudanese Battalion and led them through the battles of Atbara and Omdurman and on to Fashoda with Kitchener.
At the outbreak of the Boer War and through the intervention of Kitchener he was assigned to transport duty under Lord Roberts and remained through the occupation of Pretoria. There he was named Commissioner of Police.
In November 1900 he was posted to the War Office in the Department of Mobilization. In 1903 he took command of the 2nd Battalion of the Coldstream Guards. In August 1910 he took command of the 1st Guards Brigade at Aldershot.
In August 1914 Maxse took the 1st Guards Brigade to France. He was promoted to Major-General in October 1914 and took command of the 18th Division. The 18th Division took part in the Battle of the Somme and later captured Thiepval and the Schwaben Redoubt. At the beginning of 1917 Maxse took command of the XVIII Army Corps and was promoted to the rank of Lieutenant-General. The XVIII Corps became involved in the Fifth Army’s retreat in March 1918, and in April 1918 Maxse was to be Inspector-General of Training in France.
In May 1919, Maxse was given command of the Northern Command and remained at York until his final promotion to General, in 1923. He retired in 1926 and died at a Midhurst nursing home on 28 January 1958.