He stayed in South Africa until after the end of this war, and in November 1902 left Port Natal on the SS Ortona with the O Battery RHA, bound for Lucknow in the Bengal Presidency.

[8][16] In September 1909 he was promoted to temporary brigadier general[17] and appointed to command the artillery in one of the two Regular Army divisions garrisoned in Ireland;[4] whilst serving there, he was personally commended by King George V for saving an artilleryman from being crushed by a cavalry parade in Dublin.

[4][19] At the outbreak of the First World War in August 1914, Fanshawe, promoted to temporary brigadier general that month,[20] remained with the Wessex Division when it mobilised.

[26] V Corps was holding a position in the Ypres salient at the time Fanshawe took command, but in August it was transferred south, to support the Somme offensive.

In the final phase of the Somme fighting, at the Battle of the Ancre in November, he commanded an attack which captured Beaumont Hamel, one of the initial objectives of the offensive more than three months earlier.

It was heavily attacked in Operation Michael, the first phase of the German spring offensive of March 1918, and both it and the neighbouring VII Corps were forced to retreat, leaving a gap in the British lines.