[1][2] In May 1855, he left for the Crimean War, in which he served firstly with his battalion, then as aide-de-camp from July 1855 to the commander of the 2nd Division, Lieutenant-General Edwin Markham, and finally as deputy assistant quartermaster general from November 1855 on the staff at Headquarters, being promoted to brevet major.

He served, again as deputy adjutant general, in the 1868 Expedition to Abyssinia, for which he was appointed a Companion of the Order of the Bath and made an aide-de-camp to Queen Victoria in 1868.

He brought the Ninth Cape Frontier War to its completion in July 1878, and was made a Knight Commander of the Order of the Bath in November 1878.

[1][2] In January 1879, the official Sir Henry Bartle Frere, a personal friend of Chelmsford, engineered the outbreak of the Anglo-Zulu War by issuing the Zulu king Cetshwayo an ultimatum to effectively disband his military.

[3][4][5] Afterwards, the British government, anxious to avoid the Zulus threatening Natal, issued orders for the hasty relief of Chelmsford of his command and for him to be replaced with Sir Garnet Wolseley.

The British Army's casualties after the sharp but brief engagement was ten killed and eighty-seven wounded, in exchange for nearly sixty times that number of Zulu dead.

Chelmsford ordered Ulundi to be burnt, after which he handed over command to Wolseley on 15 July at the fort at St. Paul's and left South Africa by ship for England two days later.

The defeat of the Zulus at Ulundi allowed Chelmsford to partially recover his military prestige after the disaster at Isandlwana, and he was honoured as a Knight Grand Cross of Bath.

[8] However, he was severely criticised by a subsequent enquiry launched by the British Army into the events that had led to the Isandlwana debacle,[9] and did not serve in the field again.

[1] His sister, Julia (1833–1904), was married to Sir John Eardley Wilmot Inglis (1814–1862) who commanded the British forces during the Siege of Lucknow in 1857.