Born at Clydach in Brecknockshire, he was the son of Edward Frere, a member of an old east county family, and a nephew of John Hookham Frere, of Anti-Jacobin and Aristophanes fame.
After leaving Haileybury, Bartle Frere was appointed a writer in the Bombay civil service in 1834, and went out to India by way of Egypt, crossing the Red Sea in an open boat from Kosseir to Mokha, and sailing thence to Bombay in an Arab dhow. Having passed his examination in the native languages, he was appointed assistant collector at Poona in 1835. There he did valuable work and was in 1842 chosen as private secretary to Sir George Arthur, governor of Bombay. Two years later he became political resident at the court of the rajah of Satara, where he did much to benefit the country by the development of its communications. On the rajah's death in 1848 he administered the province both before and after its formal annexation in 1849.
In 1850 he was appointed chief commissioner of Sind, and took ample advantage of the opportunities afforded him of developing the province. He pensioned off the dispossessed amirs, improved the harbour at Karachi, where he also established municipal buildings, a museum and barracks, instituted fairs, multiplied roads, canals and schools.
Returning to India in 1857 after a well-earned rest, Frere was greeted at Karachi with news of the Indian Mutiny. His rule had been so successful that he felt he could answer for the internal peace of his province. He therefore sent his only European regiment to Multan, thus securing that strong fortress against the rebels, and sent further detachments to aid Sir John Lawrence in the Punjab. The 178 British soldiers who remained in Sind proved sufficient to extinguish such insignificant outbreaks as occurred.
His services were fully recognized by the Indian authorities, and he received the thanks of both houses of parliament and was made K.C.B He became a member of the viceroy's council in 1859, and was especially serviceable in financial matters. In 1862 he was appointed governor of Bombay, where he effected great improvements, such as the demolition of the old ramparts, and the erection of handsome public offices upon a portion of the space, the inauguration of the university buildings and the improvement of the harbour. He established the Deccan College at Poona, as well as a college for instructing natives in civil engineering. The prosperity - due to the American Civil War - which rendered these developments possible brought in its train a speculative mania, which led eventually to the disastrous failure of the Bombay Bank (1866), an affair in which, from neglecting to exercise such means of control as he possessed, Frere incurred severe and not wholly undeserved censure. In 1867 he returned to England, was made G.C.S.I, and received honorary degrees from Oxford and Cambridge; he was also appointed a member of the Indian council.
In 1872 he was sent by the foreign office to Zanzibar to negotiate a treaty with the sultan, Seyyid Burghash, for the suppression of the slave traffic. In 1875 he accompanied the prince of Wales to Egypt and India. The tour was beyond expectation successful, and to Frere, from Queen Victoria downwards, came acknowledgments of the service he had rendered in piloting the expedition. He was asked by Lord Beaconsfield to choose between being made a baronet or G.C.B He chose the former, but the queen bestowed both honours upon him.
But the greatest service that Frere undertook on behalf of his country was to be attempted not in Asia, but in Africa. Sir Bartle landed at Cape Town as high commissioner of South Africa on March 31, 1877. He had been chosen by Lord Carnarvon in the previous October as the statesman most capable of carrying his scheme of confederation into effect, and within two years it was hoped that he would be the first governor of the South African Dominion. He went out in harmony with the aims and enthusiasm of his chief, "hoping to crown by one great constructive effort the work of a bright and noble life." In this hope he was disappointed. As he stated at the close of his high commissionership, a great mistake seemed to have been made in trying to hasten what could only result from natural growth, and the state of South Africa during Frere's tenure of office was inimical to such growth.
Discord or a policy of blind drifting seemed to be the alternatives presented to Frere upon his arrival at the Cape. He chose the former as the less dangerous, and the first year of his sway was marked by a Kaffir war on the one hand and by a rupture with the Cape (Molteno—Merriman) ministry on the other. The Transkei Kaffirs were subjugated early in 1878 by General Thesiger (the 2nd Lord Chelmsford) and a small force of regular and colonial troops. The constitutional difficulty was solved by Frere dismissing his obstructive cabinet and entrusting the formation of a ministry to Mr (afterwards Sir) Gordon Sprigg.
Frere emerged successfully from a year of crisis, but the advantage was more than counterbalanced by the resignation of Lord Carnarvon early in 1878, at a time when Frere required the steadiest and most unflinching support. He had reached the conclusion that there was a widespread insurgent spirit pervading the natives, which had its focus and strength in the celibate military organization of Cetywayo and in the prestige which impunity for the outrages he had committed had gained for the Zulu king in the native mind. That organization and that evil prestige must be put an end to, if possible by moral pressure, but otherwise by force. Frere reiterated these views to the colonial office, where they found a general acceptance. When, however, Frere undertook the responsibility of forwarding, in December 1878, an ultimatum to Cetywayo, the home government abruptly discovered that a native war in South Africa was inopportune and raised difficulties about reinforcements.
Having entrusted to Lord Chelmsford the enforcement of the British demands, Frere's immediate responsibility ceased. On the January 11, 1879 the British troops crossed the Tugela, and fourteen days later the disaster of Isandhlwana was reported; and Frere, attacked and censured in the House of Commons, was but feebly defended by the government. Lord Beaconsfield, it appears, supported Frere; the majority of the cabinet were inclined to recall him. The result was the unsatisfactory compromise by which he was censured and begged to stay on. Frere wrote an elaborate justification of his conduct, which was adversely commented on by the colonial secretary (Sir Michael Hicks Beach), who "did not see why Frere should take notice of attacks; and as to the war, all African wars had been unpopular." Frere's rejoinder was that no other sufficient answer had been made to his critics, and that he wished to place one on record. "Few may now agree with my view as to the necessity of the suppression of the Zulu rebellion. Few, I fear, in this generation. But unless my countrymen are much changed, they will some day do me justice. I shall not leave a name to be permanently dishonoured."
The Zulu trouble and the disaffection that was brewing in the Transvaal reacted upon each other in the most disastrous manner. Frere had borne no part in the actual annexation of the Transvaal, which was announced by Sir Theophilus Shepstone a few days after the high commissioner's arrival at Cape Town. The delay in giving the country a constitution afforded a pretext for agitation to the malcontent Boers, a rapidly increasing minority, while the reverse at Isandhlwana had lowered British prestige. Owing to the Kaffir and Zulu wars Sir Bartle had hitherto been unable to give his undivided attention to the state of things in the Transvaal.
In April 1879 he was at last able to visit that province, and the conviction was forced upon him that the government had been unsatisfactory in many ways. The country was very unsettled. A large camp, numbering 4000 disaffected Boers, had been formed near Pretoria, and they were terrorizing the country. Frere visited them unarmed and practically alone. Even yet all might have been well, for he won the Boers' respect and liking. On the condition that the Boers dispersed, Frere undertook to present their complaints to the British government, and to urge the fulfilment of the promises that had been made to them. They parted with mutual good feeling, and the Boers did eventually disperse - on the very day upon which Frere received the telegram announcing the government's censure. He returned to Cape Town, and his journey back was in the nature of a triumph. But bad news awaited him at Government House - on the June 1, 1879 the prince imperial had met his death in Zululand - and a few hours later Frere heard that the government of the Transvaal and Natal, together with the high commissionership in the eastern part of South Africa, had been transferred from him to Sir Garnet Wolseley.
When Gladstone's ministry came into office in the spring of 1880, Lord Kimberley had no intention of recalling Frere. In June, however, a section of the Liberal party memorialized Gladstone to remove him, and the prime minister weakly complied (August 1, 1880). Upon his return Frere replied to the charges relating to his conduct respecting Afghanistan as well as South Africa, previously preferred in Gladstone's Midlothian speeches, and was preparing a fuller vindication when he died at Wimbledon from the effect of a severe chill on May 29, 1884. He was buried in St Paul's, and in 1888 a statue of Frere upon the Thames embankment was unveiled by the prince of Wales.
Frere edited the works of his uncle, Hookham Frere, and the popular story-book, Old Deccan Days, written by his daughter, Mary Frere. He was three times president of the Royal Asiatic Society.
His Life and Correspondence, by John Martineau, was published in 1895. For the South African anti-confederation view, see P. A. Molteno's Life and Times of Sir John Charles Molteno (2 vols.,London 1900).