Frederic Augustus Thesiger was born on 31 May 1827, the eldest child of Frederic Thesiger (1794-1878), a lawyer, who later became Lord High Chancellor, and his wife, Anna Maria (1799-1875), a daughter of William Tinling. Frederic senior was created 1st Baron Chelmsford on 1 March 1858. They married in 1822, and are both buried at Brompton Cemetery. His great-uncle, Sir Frederic Thesiger was aide-de-camp to Lord Nelson at the battle of Copenhagen in 1801. His brother, Charles Wemyss (1831-1903) became a general in the army, and his sister, Julia (1833-1904), married Sir John Inglis, who commanded the British during the Siege of Lucknow in 1857, and she later wrote about her experiences. His cousin was the actor, Ernest Thesiger, who is also buried at Brompton Cemetery.
An Old Etonian, young Frederic desired to serve in the Grenadier Guards, but after being refused a place in that regiment, he purchased a commissioned as ensign into the Rifle Brigade (Prince Consort’s Own) in 1844, and after serving at Halifax in Nova Scotia, Canada in the following year, he purchased an exchange as ensign and lieutenant into the Grenadier Guards in November 1845, gaining the rank of captain in 1850. In 1852 he was appointed aide-de-camp to the lord-lieutenant of Ireland, and then to the commander-in-chief of Ireland, 1853-54.
He went with his battalion on active service in the Crimea in May 1855, where he was appointed aide-de-camp from July 1855, to the commander of the 2nd Division, Lt-General Edwin Markham, and finally as deputy assistant quartermaster-general from November 1855. He was promoted brevet-major, was mentioned in despatches, and was awarded the Crimea Medal with Sebastopol clasp, the Turkish Crimea Medal, the Sardinian Crimea Medal, and the Turkish Order of the Medjidie (5th Class).
During the Indian Rebellion he commanded the 95th (Derbyshire) Regiment which marched 3000 miles across central India in 1858, and were present at the capture of Gwalior, Kotah, Pouree and Rowa. Conditions were harsh, and on just one day 89 officers and men suffered from heatstroke. During the capture of Kotah they came upon a ram tethered in a temple courtyard. It was adopted as their mascot, and the tradition has continued with its successor regiments.
He stayed on in the sub-continent, mostly in staff posts, and on 1 January 1867, at Bombay, he married Adria Fanny (1845-1926), the first daughter of Major-General John Coussmaker Heath, of the Bombay Army, and they had six sons, although one died as an infant in 1872, and Alfred Sullivan died aged eight in 1889, and was buried at Brompton. The eldest, Frederic John Napier, became the 3rd Baron/1st Viscount Chelmsford, and all the surviving sons went on to have distinguished careers in the army and administration.
In 1868 he served as deputy adjutant-general to the methodical and dignified Sir Robert Napier during the Abyssinian Expedition, which set out to release British prisoners who had been held against their will for four years by the brutal Emperor Theodore. In his capacity as the deputy adjutant-general, Lord Chelmsford must be able to claim a considerable share of the organisational success in what was considered to be one of the most remarkable military feats of the Victorian era. 15,000 fighting men started from an improvised port on the Red Sea, advanced over 650 kilometres across unknown territory in tropical conditions to the Abyssinian capital at Magdala, constructing a road as they went, and dragging a vast arsenal of heavy weaponry, including mountain guns, with them. Lord Napier was not always forthcoming with praise, referred in his despatch to Chelmsford’s ‘great ability and untiring energy.’ Napier rescued the prisoners, broke the spirit of the enemy, and Theodore was killed during the capture of Magdala. With no intention of annexation, the British withdrew in safety, with honour satisfied.
In the following year he went back to India, where he was advanced to adjutant-general and remained until 1874, and became major-general.
He took over command of the troops who were already engaged in the putting down of a tribal rebellion known as the 9th (Xhosa) Cape Frontier War, which was raging in the north-east region of Cape Colony. The campaign followed the usual pattern of Frontier Wars. The rebels took refuge in broken country and thick scrub, until they were flushed out and rounded up, and their leaders captured or killed. When the rebels eventually lost heart by the middle of the year and the campaign was brought to a close, Lord Chelmsford turned his attention to the Zulu problem.
He was without doubt made a scapegoat to a certain degree for the failings of the Zulu War, and he was heavily criticised for his tactics on that fateful day at Isandlwana, on 22 January 1879, before becoming the victor at the final battle of the campaign at Ulundi on 4 July 1879.
He never lost the respect of most of the men who served under him. For instance, under the title ‘Zulu Veterans’ Presentation’ the Sydney Telegraph of 8 March 1913 carried a report about a presentation to his son, Frederick John Napier, 1st Viscount Chelmsford, who was the retiring Governor of New South Wales, which stated:
‘Lord Chelmsford was yesterday the recipient of an address from a number of soldiers who fought in the Zulu and Kaffir wars. The retiring Governor is the son of an officer who rendered distinguished service in the Zulu campaign.
Colour-Sergeant Jeffes, who was of the [90th] Perthshires, was responsible for the movement, which led to the veterans waiting upon Lord Chelmsford, and he feelingly spoke of the regard in which his Excellency's father was held as a kind and renowned commander and a gallant soldier. The address was signed by men from the 17th Lancers (‘Death and Glory Boys’), the 94th Regiment, the Frontier Mounted Police, and the warships Pym and Shah.
Lord Chelmsford expressed himself as deeply grateful for the honour that was paid his father's name. ‘My father,’ he said, "always spoke of his old soldiers in most affectionate terms, and after his death I had proof of his kindness and generosity towards them. I, therefore, particularly esteem this address, which, I know, will bring great pleasure to, my mother when I present it to her. It will be to her and my brother a source of comfort, and may I say how deeply I value the tribute you have paid my father's memory.’
Part of the address remarked: ‘Proud indeed are our hearts today that the son of our commander has, by his great virtues and abilities, so endeared himself to the people of this great and glorious land of Australia. We wish to express our gratitude, love, and respect for the honoured name of Chelmsford.’
Lord Chelmsford became lieutenant-general in 1882, and full general in 1888. He was lieutenant of the Tower of London from 1884 to 1889; colonel of the 4th (West London) Rifle Volunteer Corps in 1887, colonel of the Sherwood Foresters in 1898, and he was appointed colonel of the 2nd Life Guards in 1900. He was Gold Stick in Waiting during ceremonial events at Court, and he was the inaugural governor and commandant of the Church Lads Brigade. He was appointed Knight Grand Cross of the Royal Victorian Order (GCVO) during the November 1902 King Edward VII Birthday Honours list.
General Thesiger was playing billiards at the Royal United Services Club in Pall Mall when he suffered a seizure and died on 9 April 1905, aged 77. He was buried among other members of his family in Brompton Cemetery, London.