He served as Commander-in-Chief of British Forces in South Africa during the early months of the Second Boer War and subsequently commanded the army in Natal until his return to England in November 1900.

Buller was the second son and eventual heir of James Wentworth Buller (1798–1865), MP for Exeter, by his wife Charlotte Juliana Jane Howard-Molyneux-Howard (d.1855), third daughter of Lord Henry Thomas Howard-Molyneux-Howard, Deputy Earl Marshal and younger brother of Bernard Howard, 12th Duke of Norfolk.

His VC citation, for actions taken during the Battle of Hlobane, reads: For his gallant conduct at the retreat at Inhlobana, on the 28th March, 1879, in having assisted, whilst hotly pursued by Zulus, in rescuing Captain C. D'Arcy, of the Frontier Light Horse, who was retiring on foot, and carrying him on his horse until he overtook the rear guard.

[5]In an interview to The Register newspaper of Adelaide, South Australia, dated 2 June 1917, Trooper George Ashby of the Frontier Light Horse (also referred to as "Pulleine's Pets") attached to the 24th Regiment gave an account of his rescue by Col. Buller: ... it was discovered that the mountain was surrounded by a vast horde of Zulus.

Ashby and his little party endeavoured to fight their way down, and at last he and a man named Andrew Gemmell, now living in New Zealand, were the only ones left.

They eventually reached the main camp, and for this service, as well as for saving the lives of two fellow-officers on the same occasion, Col. Buller received the Victoria Cross.

"[6]In the First Boer War of 1881 he was Sir Evelyn Wood's chief of staff and the following year was again head of intelligence, this time in the Egypt campaign, and was knighted.

He had married Audrey, the daughter of the 4th Marquess Townshend, in 1882 and in the same year was sent to the Sudan in command of an infantry brigade and fought at the battles of El Teb and Tamai, and the expedition to relieve General Gordon in 1885.

By early September 1899 he had serious thoughts that the Boers could not easily be browbeaten, and that White's forces in Natal might receive some punishment if they deployed too far forward.

Because of concerns about his performance and negative reports from the field he was replaced in January 1900 as overall commander in South Africa by Lord Roberts.

He remained as second-in-command and suffered two more setbacks in his attempts to relieve Ladysmith at the battles of Spion Kop and Vaal Krantz.

On his fourth attempt, Buller was victorious in the Battle of the Tugela Heights, lifting the siege on 28 February 1900, the day after Piet Cronje at last surrendered to Roberts at Paardeberg.

When public disquiet emerged over the continuing guerrilla activities by the defeated Boers, the Minister for War, St. John Brodrick and Lord Roberts sought a scapegoat.

The matter came to a head when a virulent piece written by The Times journalist Leo Amery was publicly answered by Buller in a speech on 10 October 1901.

[20] Buller continued his quiet retirement, until on 29 May 1907 he accepted the post of Principal Warden of the Goldsmiths' Company which he held until his death in 1908.

The entire western side of the chancel arch inside the church forms an elaborate monument to Sir Redvers.

As he died without male progeny he was succeeded in the family estates by his next surviving younger brother Arthur Tremayne Buller (born 1850), his father's fifth son.

[2] Historian Richard Holmes (1946–2011) commented that Buller has gone down as "one of the bad jokes of Victorian military history", and quotes a famous verdict that he was "an admirable captain, an adequate major, a barely satisfactory colonel and a disastrous general".

In January 2021, Exeter City Council voted to move the statue away from the college on the grounds that its connection to "British imperialism" meant it was "inappropriate" to be "outside an educational establishment which includes young people from diverse backgrounds".

[30][31] The entire western side of the chancel arch inside Holy Cross Church in Crediton forms an elaborate monument to Buller, designed by William Douglas Caröe with sculpture of St George by Nathaniel Hitch (1845–1938).