Zanzibar Slave Trade And The British Involvement In Stopping it.

Graham Charles Lear
14 min readAug 28, 2020

The early history of Zanzibar

Round 1500 Portugal gained control of Zanzibar and most of the East African coast. Then in In, 1698 Arabs from Oman ousted the Portuguese. In 1792 Britain signed a treaty with the Sultan of Muscat providing British protection for Zanzibar in exchange for Omani support against any French thrust via Oman towards India. So started a gradual British involvement in Zanzibar affairs.

The Omani Arabs only started to take a serious interest in Zanzibar, when Sayyid Said, Sultan of Muscat since 1804 encouraged merchants to trade with, or move to, the island, and to expand into mainland Africa. In 1840 he moved his capital from Muscat to Zanzibar, where he presided over a flourishing trading empire.

In 1856 Said died on a voyage back to Zanzibar from Muscat. His house did not have fixed rules of succession, but he had nominated his third son, Thwain, as Sultan of Oman, and (after his second son, Khalid, had died) his fourth son, Majid, as Sultan of Zanzibar. During Said’s absence, Majid had been acting governor of the African dominions. A younger son, Barghash, who had travelled with his father, attempted to usurp the throne upon returning to Zanzibar but failed due to the loyalty of the Sultan’s troops to Majid. Thwain initially refused to recognise Majid, and attempted an invasion in March 1859, but was turned back by the Indian Navy ship Punjab. The following October, Barghash, encouraged by the French, attempted a military uprising, but this was suppressed by British sailors from the Assaye and Lynx, and Barghash was exiled to Bombay. These British actions increased the dependence of the new Sultan on British support. Colonel (Sir) William Marcus Coghlan, British political resident at Aden and Rev. George Percy Badger were appointed to arbitrate — in name of Lord Canning, Governor-General of India — between Majid and Thwain. The latter agreed to accept the separation of the two sultanates for annual compensation of 40,000 Maria Therese dollars to be paid by Majid. In 1862 Britain and France agreed to the settlement and pledged to recognise the independence of the two sultans. Majid suspended payments in 1866 when Thwain was deposed and murdered by his own son, Salim, who suffered the same fate soon after at the hand of his kinsman, Azzan.

Majid’s reign witnessed further economic growth in Zanzibar, but in October 1870 he died, without a male heir. Barghash, who was his only half-brother to have reached majority and residing at Zanzibar, was the obvious candidate to succeed him, especially since his stay at Bombay had broadened his outlook and sense of political reality. The British Consul at Zanzibar, Henry Adrian Churchill, assured him of British support, and he, in turn, promised the latter to honour the agreements with his two predecessors and — ultimately — to abolish the slave trade. In the years preceding his accession, however, he had also come under the influence of the fundamentalist, anti-Western mutawi’ah, and was barely in power when he renounced his agreements with Churchill, who angrily reported that “it is to be regretted that there should not be at the present moment in Zanzibar anyone to dispute the succession”.

Soon after, however, two events occurred to restore matters. Firstly, ill-health forced Churchill to leave Zanzibar, and he was succeeded by Dr John Kirk, agency surgeon and vice-consul, who had known Barghash for some time and had a good understanding with him. Secondly, another of Barghash’s half-brothers, Turki, who had recently seized the throne in Muscat in yet another palace revolt, obviously had eyes on Zanzibar, and Barghash could not risk losing British support. Three months after taking office Kirk could report to London that a good working relationship had been restored (and this was to persist for the 16 years they were associated with each other).

The Zanzibar slave trade

The slave trade from Zanzibar had started soon after the Arab conquest, initially for the date plantations in Arabia. Although slaves were also supplied to Persian and India, it was the establishment of sugar and clove plantations in Mauritius and Reunion in the 18th century which led to the greatest development of the trade.

In 1811, just four years after Britain had abolished slavery, Said opened the Great Slave Market in Zanzibar; a year later he introduced cloves to the island, generating a significant need for slaves on the island itself. In 1822, the Sultan’s dependence on British naval strength allowed Governor Sir Robert Townsend Farquhar of Mauritius (which under French rule had been a primary destination of slavers from Zanzibar) to send Captain Fairfax Moresby, a senior officer at that island, in the Menai to conclude a treaty limiting the slave traffic to the Sultans own (East African and Arabic) dominions and forbidding any trade of slaves to Christians. A later treaty, effective from 1847, and negotiated in 1845 by Colonel Atkins Hammerton (appointed as the first British Consul at Zanzibar in 1841) further limited — in theory — the traffic from Zanzibar to the Sultan’s African dominions between Lamu in the north and Kilwa in the south.

Prevention of incursion by other European powers was the initial reason for a British naval presence on the East African coast. To this were later added protection of British traders, and suppression of the slave trade. This last factor only became prominent round 1860, when the Foreign Office requesting a ship permanently on the station for that purpose. Lack of knowledge about the trade, and a desire not to offend Britain’s ally, the Sultan, were responsible for the later development of the anti-slavery issue on the East Coast than on the West coast. The explorations of David Livingstone, Richard Burton and John Speke increased the interest of the British public in the area.

The small number of British cruisers on the station, and the fact that large numbers of comparatively small dhows were involved in the slave trade, meant that much of the navy’s patrol work had to be done in ships boats, often working independently for days on end.

Poor communications with home, and lack of explicit instructions from the Admiralty, meant that the ship’s commanders had to decide how to proceed in individual cases; destruction of captured dhows on the spot was often considered to be the only viable alternative. Protest against this procedure led in 1869 to the giving of full powers of adjudication to the Vice-Admiralty Court at Zanzibar (established in 1866, then only for slavers captured within the Sultans dominions), to which all captures had then to be taken, and to “clarification” of the general instructions to the commanders on the station (often irrelevant, being based on those for the West African station), which in fact only made them more unclear. These aspects, together with the small number of ships on the station (generally not more than two; see for example Cummings report for 1872 meant that the navy’s impact on the slave trade was minimal.

The frustratingly limited progress in the field sparked debate at home: both within and outside parliament. Lobbying by humanitarian bodies such as the Church Missionary Society and the Anti-Slavery Society, and public meetings such as those addressed by Sir Bartle Frere the former Governor of Bombay and an advocate of an aggressive British policy in East Africa (and elsewhere), persuaded Gladstone’s government to establish a Select Committee in July 1871. This Committee, which contained a number of vocal parliamentary humanists, concluded that a major effort should be made to persuade the Sultan of Zanzibar to ban the trade completely.

The Frere Mission

By mid-1872 it had been decided that a special mission, led by Sir Bartle Frere, would go to Zanzibar to negotiate a new treaty with Barghash. As hoped by the government, Frere’s appointment was popular with the British press and public.

Captain Charles Jago of the Briton was to have been Frere’s naval advisor, but — after accepting the position — he broke his leg and had to go to Seychelles to recuperate, whereas Dr Loney recorded in his medical journal he was encountered by Glasgow in September. He was ultimately replaced by Captain Henry Fairfax. The Reverend George Badger was Frere’s confidential advisor and interpreter, although he became ill at Zanzibar and had to return prematurely to England.

The Frere Mission, Cairo, 22 December 1872
Sir Bartle Frere, Rev. G.P. Badger,
Mr Clement Hill, Capt. Fairfax, Major Ewan Smith, Mr C. Grey, Mr B.C.A. Frere

Frere’s party travelled overland to Paris and Rome — where the support of the French Foreign Minister, Comte de Rémusat, and the Pope was solicited; in the first case with only limited success. They were then conveyed from Brindisi to Zanzibar by the Admiralty yacht Enchantress, arriving at the latter place on 12 January 1873. Rear-Admiral Cumming’s flagship Glasgow, and the cruisers Briton (Captain George John Malcolm) and Daphne (Captain Richard Sacneverell Bateman) were already present.

Despite an auspicious beginning — with much ceremonial pomp when the mission members visited the Sultan’s palace on the 13th, and when he visited Enchantress the next day — it soon became obvious that Barghash, and more particularly his advisors, were not prepared to sign Frere’s draft treaty. Much of the negotiating was done by Badger, who was instructed by Frere to convey that (i) the British Government would protect the Sultan from any antagonism his compliance with their wishes might provoke, the French, German, American and Portuguese governments all supported the mission, and if the treaty was not concluded “the only adult working slaves, the lawful property of His Highness or his subjects other than notorious slave traders” would be allowed by the navy to land at Zanzibar so that the supply of fresh slaves would be stopped anyway. Barghash repeated that the abolition of slavery would ruin the agriculture of Zanzibar — already seriously damaged by the previous year's hurricane and lead to a rebellion on the island; furthermore, slavery was endorsed by Moslem law. Nonetheless, he still did not definitely reject the treaty.

Frere decided to give the Sultan a little time to reconsider his position. On 3 February he set off on a tour of inspection to Pemba and Dar-es-Salaam. When he returned on the 8th, Kirk had encouraging news. In an interview on the 4th, Barghash had intimated that he might be prepared to accept the treaty if its operation could be delayed for some time. Frere formally suggested this as a basis for further negotiation, but — after a delay of several days — Barghash unexpectedly wrote “You request that we signify to you either our acceptance or our refusal. In one word, No.”

On 15 February Frere set out on another tour of inspection, this time along the southward coast, as far as the Comoro Islands. He found that news of the rejection of the treaty had travelled before him, together with an opinion that this was the result of French diplomacy. At the end of March, he left Zanzibar with Rear-Admiral Cumming in Glasgow and proceeded to Muscat, where on 14 April Turki, who had less to lose, agreed to a treaty ending slavery in his dominions.

What had caused Barghash’s unexpected rejection of the treaty, when he had appeared to be moving towards acceptance? Before negotiations started the British government had attempted to maximise international support. Although the German traders on the coast were opposed to the treaty, the German Foreign Minister, Delbrück, instructed the German consul, Theodor Schultz, to support Frere, and — once these instructions arrived — this he loyally did. The United States Secretary of State, Hamilton Fish, similarly instructed both the American consul, W. G. Webb, and Captain Wilson of U.S.S. Yantic on the station, to co-operate with Frere “in any proper way to secure the success of his mission”. This Wilson indeed tried to do — in fact, he rather naïvely tried to secure his own treaty before Frere arrived, but was hindered by his lack of knowledge of the Arabic language. Webb, on the other hand, for reasons which are not clear, choose to interpret his instructions as being “limited to intimating to the Sultan of Zanzibar the wish of the government of the United States that the exportation of domestic slaves from the Zanzibar dominions to Muscat should cease”.

Although Webb’s attitude may have helped to harden Barghash against the treaty, it was the French consul, de Vienne, who did the most damage. He had been in Paris when Frere called there and arrived back in Zanzibar on 9 February, the day after Frere had returned from his first tour of inspection, and when Barghash was on the point of yielding. The next day de Vienne called on Barghash. Although it is uncertain which of the two made it, a suggestion was apparently made that the Sultan should apply for French protectorate status. This conversation gave Barghash sufficient encouragement to reject the treaty. Although Paris subsequently made clear that this was out of the question, the damage had been done.

En route to Muscat, Frere finalised instructions to Kirk which he had been formulating since it became clear that failure was a possibility. He considered that (i) under Hammerton’s 1845 treaty, the shipment of slaves from the mainland to Zanzibar should be considered piracy, (ii) the right of Zanzibar subjects to ship their domestic slaves from port to port within the Zanzibar dominions should be withdrawn, (iii) all slave markets should be closed, (iv) an embargo should be placed on the customs-houses to prevent the passage of slaves, and (v) the Naval squadron should be radically increased to 14 ships; these measures were to start on 1 May.

When these proposals became known in London, the initial reaction was consternation: the Law Officers of the Crown concluded that in particular Frere’s 2nd proposal “imposed terms upon the Sultan not imposed by the treaty of 1845”, and would furthermore infringe the Sultan’s independence which Britain and France had guaranteed since 1862, and would, therefore “amount to an act of war”. Lord Granville, the Foreign Secretary, instructed Kirk to “withhold further measures in that direction with as little ostensible retraction as possible”.

A further consideration, however, led to the conclusion that if force was to be used, it could be better used to secure the new treaty, than to take questionable action under the old one. Kirk was now instructed that “you will state to the Sultan that if the treaty … is not signed by him before the arrival of Admiral Cumming who is ordered to proceed at once to Zanzibar, the British naval force will proceed to blockade the island of Zanzibar”. Cumming was indeed so instructed, and was, with all available ships (these were — in addition to Glasgow, and to Briton and Daphne which were already on the station: Wolverine, Nimble, Vulture and Magpie), to “establish [a] Blockade of [the] Island, and enforce it according to the Law of Nations”.

Malcolm in Briton was instructed to await the arrival of the fleet at Zanzibar. In consultation with Kerk, however, he decided to implement a mini-blockade straight away; in this, he was soon joined by Bateman in Daphne.

When Barghash saw the effects of Malcolm’s activities and was informed by Kirk of the instructions to Cumming, he realised that he had no alternative but to ratify the treaty, which he did on 5 June (Cumming subsequently arrived on 23 June). All transport of slaves over the water was to be prohibited, all public slave markets were to close, liberated slaves were to be protected by the Sultan, and Indian subjects were to be prohibited from owning slaves. Kirk made sure that the Sultans advisors were fully involved in accepting the treaty so that it could not form grounds for them to overthrow him. Although overland slave traffic, and some traffic between the mainland and the island, persisted for many years, necessitating the stationing of a stationary depot ship (London) at Zanzibar, Barghash generally carried out the terms of the treaty to the best of his ability. In 1878 he signed decrees prohibiting slave caravans from the interior to the coast, and along the coast. British support enabled him to survive the storm of protest these measures engendered.

Rear Admiral Cummings report for 1872.

Rear-Admiral Cumming to the Secretary to the Admiralty.

“Glasgow,” at Zanzibar, January 10, I873.


IN accordance with the directions contained in the Slave Trade Instructions, I beg to forward, to be laid before the Lords Commissioners of the Admiralty, the following Report for the year 1872.

2. On my assuming command of this station on the 21st March 1872, I found Her Majestys ships “Wolverene” and “Columbine” employed on the East Coast of Africa and the Mozambique Channel, cruizing for the suppression of the Slave Trade. “Briton” and “Magpie” were at Bombay.

3. On the 10th April “Magpie” left Bombay to relieve “Columbine,” and the latter ship proceeded to Trincomalee. “Magpie” relieved “ Columbine “ off Ras Hafoon in May, and remained in that neighbourhood until 2nd June, Left Zanzibar on 23rd July for the Mozambique Channel, where she remained cruizing until 3rd December, on which date returned to Zanzibar. Having completed provisions, left for Bombay, relieved by “Daphne.” During the time she was employed on the East Coast of Africa (May to December} “ Magpie” captured three dhows.

4. “Wolverene” remained on East Coast of Africa from March to 30th November, when she left for Seychelles, thence to proceed to Bombay. During this period “Wolverene” captured one dhow. Has been relieved by “Briton.”

5. “Briton “ left Bombay on 8th May for Muscat, to send “Bullfinch “ to England, and, on being relieved by “Vulture,” left that place to cruze between Ras-el-Had and Aden; owing to an accident to her screw had to return to Bombay; on defect being made good, left again for her station, but, when nearing Socotra, Captain Jago having fractured his leg, had to proceed to Seychelles, for the purpose of landing him at sick-quarters. Having so done, left for Aden, remained cruizing in the vicinity of that place, visiting occasionally Socotra, Abd-el-Kuri, and Guardafui, until 1st December, when she proceeded to Zanzibar, where she arrived on 15th. “Briton” has not made any capture.

6. “Vulture,” on 6th September, off Ras-el-Had, captured a dhow with 169 slaves on board.

7. The inclosed Report gives the detailed account of the captures affected during the nine months I have had command of the Station. The following is a condensed abstract of the Report: -

Number of dhows captured 6

The tonnage of captured dhows 992.48

Number of slaves liberated251

8. There being only nine ships on the station, including the flag-ship, and having out of that number to keep six employed in Indian waters, leaves only two available for service on the whole of the Coast of Africa, from Cape Guardafui to the southern limits of the station (about 2,500 miles); these vessels can only be relieved one at a time, and that only when the flag-ship is in India, and is one of the six vessels there.

9. In order that the two ships employed cruising on the East Coast of Africa should be enabled to keep up, as much as possible, surveillance over the line of coast entrusted to them, I would beg to suggest that a steam pinnace should be attached to each of the ships thus employed.

10. With reference to the disposal of the liberated slaves, Captain Wratislaw reports that those (seventy-nine in number) onboard the last dhow he captured (27th September last) were all handed over to the French Mission at Zanzibar. I would suggest that, for the future, at all events for some time to come, all liberated slaves should be sent to the Seychelles Islands; labour is much wanted there, and the resources of the islands are capable of development; but the system of supervision and seeing that the labourers are properly allotted, looked after, and cared for, is open to much improvement. There are several public works, such as a pier, roads across to the Island of Mahé, &c., in progress, but which get on slowly for want of labour.

ll. In my letter of the 28th December last, I have forwarded a request from the King of Johanna that liberated slaves may be sent to that place, to be treated as free labourers and paid accordingly, but I question the policy of complying with this request.

12. The number of slaves that passed through the Custom-house at Zanzibar during the year 1872, I have ascertained to be about as follows (from 1st May to 31st December)

Shipped from Quiloa and landed at Zanzibar 14,721

Shipped from other villages and ports on the coast and landed at Zanzibar 408

Total 15,129

For the above duty was paid, but no account taken of the contraband introduction of slaves, which has been considerable.

Slaves exported from Zanzibar to Pembra-Lamoo, &c., under the Sultans pass 9,381

No account is here taken of those smuggled away, which number also has been considerable.

I have, &c.
(Signed) A. CUMMING.



Graham Charles Lear

What is life without a little controversy in it? Quite boring and sterile would be my answer.