► Royal Navy ► Slave trade legislation
Enlightened opinion caused a number of countries to declare the slave trade (but not necessarily slavery itself) illegal during or after the period of the Napoleonic wars. The Congress of Vienna - which rearranged Europe in 1815 - issued a high-sounding condemnation of the trade, but did not go so far as to ban it. Legislation alone, however, was not enough to bring the trade to an end, and it was many years before officials in slave-holding areas (notably Brazil and the Spanish colony of Cuba, but also the (southern) United States) loyally and effectively implemented national policy. British policy was aimed at making bilateral treaties with other nations giving the Royal Navy the right to detain suspected slavers and submit them to trial. This policy was given added impetus in 1817 by the judgement of the High Court of Admiralty in the case of the French slaver Louis, stating that the fact that slavery was illegal in the country under whose flag the ship was sailing, did not give the Royal Navy sufficient right to detain a slaver unless that right was explicitly granted by treaty.
The treaties applied initially only to ships actually carrying slaves when intercepted (which often led to slaves being rapidly landed - or even thrown overboard - when a Navy cruiser was sighted). This was later extended to ships which had being carrying slaves, and finally to ships which had not yet carried them, but were obviously intending to do so. The so-called "equipment clause" in later treaties typically allowed seizure if any of the following items were found on board:- hatches with open gratings, instead of the close hatches which are used in merchant vessels
- divisions, or bulkheads, in the hold or on deck, in greater number than are necessary for vessels engaged in lawful trade
- spare planks fitted for being laid down as a second or slave deck
- shackles, bolts, or handcuffs
- a larger quantity of water, in casks or tanks, than is requisite for the consumption of the crew
- an extraordinary number of water casks, or of other receptacles for holding liquid
- a greater number of mess tubs or kids than are requisite for the use of the crew
- a boiler, of other cooking apparatus, of an unusual size
- an extraordinary quantity of rice, or farena, or any other article of food beyond the probable wants of the crew
- a quantity of mats or matting greater than is necessary for the use of such merchant vessels.
British (or stateless) slavers were tried at Vice-Admiralty courts, for example at Freetown (Sierra Leone), St Helena or the Cape of Good Hope. Although many treaties stipulated that "Mixed Commission" courts be established on territories of both signatories, some countries (notably France and - initially - the United States) did not allow the Royal Navy the right of search, and insisted that intercepted slavers could only be tried in national courts.
| Treaty | Locations of Mixed Commission courts | Note |
| 1817 Portugal | Freetown, Rio de Janeiro | Established in 1819. Only Freetown after Brazilian independence; defunct in 1839 |
| 1817 Spain | Freetown, Havana | Established in 1819 |
| 1818 Netherlands | Freetown, Surinam | Established in 1819 |
| 1828 Brazil | Freetown, Rio de Janeiro | Pursuant to old treaty with Portugal; lapsed in 1845 |
| 1839 Chile | Freetown | No Chilean court |
| 1839 Argentine | Freetown | No Argentine court |
| 1839 Uruguay | Freetown | No Uruguayan court |
| 1840 Bolivia | Freetown | No Bolivian court |
| 1841 Ecuador | Freetown | No Ecuadorian court |
| 1842 Portugal | Cape of Good Hope, Spanish Town (Jamaica), Luanda (Angola), Boa Vista (Cape Verde Is.) | Established in 1844. Spanish Town and Boa Vista closed in 1851 |
| 1862 United States | Freetown, Cape of Good Hope, New York |
In the period between 1819 and 1845 the Mixed Commission courts (and particularly those at Freetown) were responsible for the majority of trials (Freetown, Spanish: 241; Freetown, Portuguese: 155; Freetown, Brazilian: 111, Freetown, Dutch: 21, Havana: 50; Rio de Janeiro: 44; Surinam: 1). In 1839, where Portugal refused to renew the treaty, Palmerston introduced a law (2 & 3 Vict c. 73) allowing Portuguese vessels to be tried at Vice Admiralty courts (although without punishment of master or crew). Three years later a new treaty was agreed, including - for the first time - effective Portuguese penalties. As a result of this Portuguese slavers abandoned their national flag, and now being stateless could not be tried at the new Anglo-Portuguese Mixed Commission courts. Similar legislative developments in Spain in 1845, and Brazilian refusal to extend its treaty in the same year, resulted in transfer of Spanish and Brazilian cases from Mixed Commission to Vice Admiralty courts. After 1845 few cases were tried at Mixed Commission courts, and they were all formally disbanded in the 1870s.
Developments per country:
| Britain | |
| 1788 | 28 Geo III c. 54 (An Act to regulate, for a limited Time, the shipping and carrying Slaves in British Vessels from the Coast of Africa; the so-called "Dolben Act"): first measure to improve conditions on slave ships, and to require a surgeon on board slave ships. Renewed annually (except in 1796 by oversight) |
| 1807, 25 Mar | 47 Geo III c. 36 (An act for the abolition of the slave trade): end of British slave trade, penalty = forfeiture of vessel and £100 fine per slave |
| 1808 | first British anti-slavery patrol on West African coast (frigate Solebay and sloop Derwent) |
| 1810 | first effective RN squadron on the coast |
| 1811, 14 May | 51 Geo III c. 23 (An act for rendering more effectual an act made in the forty-seventh year of His Majesty's reign, intitled "An act for the abolition of the slave trade"; the so-called "Felony act"): slave trade a felony, punishable by 14 years transportation |
| 1815, 9 Jun | Congress of Vienna condemns, but does not ban, slave trade |
| 1817, 15 Dec | High Court of Admiralty judge Sir William Scott (later Lord Stowell) gives verdict in case of French slaver Louis (captured by Queen Charlotte); search and capture of ships under foreign flag only possible if specifically allowed by treaty |
| 1819 | RN established independent West African station |
| 1824 | 5 Geo IV c. 17 (An Act for the more effectual Suppression of the African Slave Trade): slave trade considered equivalent to piracy, and punishable by death |
| 1833 | 3&4 Will IV c. 73 (An act for the abolition of slavery throughout the British colonies, for promoting the industry of the manumitted slaves, and for compensating the persons hitherto entitled to the services of such slaves; the so-called "Emancipation act"): slavery abolished in British colonies (except India and St Helena) as of 1 August 1834; slaves to be compulsory "apprentices" until 1840 |
| 1837 | 7 Will IV & 1 Vict c. 88 (An act to amend certain acts relating to the crime of piracy): slave trade punishment reduced to transportation for life |
| 1838, July | West Indian planters agree - under government pressure - to end "apprenticeship" of ex-slaves |
| 1841 | Denman destroys slave barracoons in the Gallenas river |
| 1841 | first treaties with African chiefs |
| 1841 | Niger expedition |
| 1842 | "Aberdeen letter" expresses doubts about legality of barracoon attacks, restricts navy campaign; Gallenas slaver Buron sues Denman for damages |
| 1843 | 6&7 Vict c. 98 (An act for the more effectual suppression of the slave trade): extends prohibition to all British subjects, wherever domiciled |
| 1846 | free trade: market opened to "slave sugar" |
| 1847 | treaty making with African chiefs resumes |
| 1848 | Denman wins case brought by Buron |
| Argentine (independent from Spain in 1816) | |
| 1839, 24 May | treaty: right of search and Mixed Commission court (only at Freetown, no Argentine commissioner) |
| Austria | |
| 1841, 20 Dec | Quintuple treaty; right of search in Atlantic and Indian oceans, equipment clause |
| Bolivia (independent from Spain in 1825) | |
| 1840, 25 Sep | treaty: right of search and Mixed Commission court (only at Freetown, no Bolivian commissioner) |
| Brazil (independent from Portugal in 1822) | |
| 1825 | old Portuguese treaties to apply; Mixed Commission courts at Rio and Freetown |
| 1826, 23 Nov | treaty: import of slaves to be illegal after 1829 |
| 1845 | treaty of 1826 lapsed and not replaced; Mixed Courts at Rio and Freetown closed. Britain takes unilateral action: "Aberdeen Act" (8 & 9 Vict c. 122) allows Vice Admiralty courts to try Brazilian ships |
| 1849 | unilateral British action starts in Brazilian waters |
| 1853 | trade ends |
| 1888 | slavery abolished |
| Chile (independent from Spain in 1818) | |
| 1839, 19 Jan | treaty: right of search and Mixed Commission court (only at Freetown, no Chilean commissioner) |
| Denmark | |
| 1792 | law ending slave trade in 1802 |
| 1802 | slave trade illegal |
| 1834, 26 Jul | treaty: national courts |
| Ecuador (independent from Spain in 1830) | |
| 1841, 24 May | treaty: right of search and Mixed Commission court (only at Freetown, no Ecuadorian commissioner) |
| France | |
| 1794, 4 Feb | slavery abolished in French colonies (decree of 16 Pluviôse II) |
| 1801 | slavery reintroduced by Napoleon |
| 1814 | Treaty of Paris: slave trade limited to French colonies; trade to end in 5 years |
| 1818 | slave trade illegal |
| 1828 | French anti-slavery patrol |
| 1831, 31 Nov | Convention: right of search 15N-10S, 0-30W, trial by national courts, no equipment clause |
| 1833, 22 Mar | Convention: equipment clause added Instructions to Cruizers |
| 1841 | Quintuple treaty; right of search in Atlantic and Indian oceans, equipment clause; not ratified |
| 1845, 29 May | treaty: national courts, no right of search, French squadron on the West African coast |
| 1848, 27 Apr | slavery abolished by the 2nd Republic |
| 1855 | treaty of 1845 expires |
| Hanse towns | |
| 1837, 9 Jun | treaty: right of search and national courts |
| Haiti (independent from France in 1804) | |
| 1839, 23 Dec | treaty: right of search and national courts |
| Netherlands | |
| 1814 | slave trade illegal |
| 1818, 4 May | Treaty: right of search and Mixed Commission courts at Freetown and Surinam Instructions for the Ships of the British and Netherlands Royal Navies, employed to prevent the Traffic in Slaves Regulations for the Mixed Commissions, which are to reside on the Coast of Africa, and in a Colonial Possession of His Majesty the King of the Netherlands |
| 1822, 31 Dec | Articles explanatory of and additional to this treaty: condemnation if slaves had been carried, replacement of Commissioners |
| 1823, 25 Jan | Further additional Article: equipment clause |
| 1830 | slave trade ends |
| 1863 | slavery abolished |
| Portugal | |
| 1810, 19 Feb | treaty: only slaving from Portuguese possessions in Africa (and Whydah and the Gold Coast) |
| 1815, 22 Jan | Treaty: slave trade illegal north of the equator Additional Article: Portuguese settlers may take domestic slaves if retiring to Portuguese territories north of the line |
| 1817, 28 Jul | Additional Convention: right of search and Mixed Commission courts in Sierra Leone and at Rio Form of Passport for Portuguese Vessels destined for the lawful Traffic in Slaves Instructions intended for the British and Portuguese Ships of War employed to prevent the illicit Traffic in Slaves Regulations for the Mixed Commissions, which are to reside on the Coast of Africa, in the Brazils and London Commission for a British Commissary-Judge, a Commissioner of Arbitration, and a Secretary or Registrar in Sierra Leone Separate Article |
| 1819, 3 Apr | Declaration: correcting clerical error |
| 1823, 15 Mar | Additional Articles to the Convention: equipment clause added |
| 1839, 24 Aug | failure to agree to new treaty results in British law (2 & 3 Vict c. 73) to allow Portuguese vessels to be tried at Vice Admiralty courts; Mixed Commission court at Freetown defunct |
| 1842, 3 Jul | treaty: new Mixed Commission courts at Luanda, Boa Vista, Spanish Town and Cape of Good Hope; stringent Portuguese legislation; Portuguese flag no longer used by slavers |
| Prussia | |
| 1841, 20 Dec | Quintuple treaty; right of search in Atlantic and Indian oceans, equipment clause |
| Russia | |
| 1841, 20 Dec | Quintuple treaty; right of search in Atlantic and Indian oceans, equipment clause |
| Sardinia | |
| 1834, 8 Aug | treaty: right of search and national courts |
| two Sicilies | |
| 1838, 14 Feb | treaty: right of search and national courts |
| Spain | |
| 1808 | treaty |
| 1817, 23 Sep | Treaty: slave trade illegal north of the equator, right of search, Mixed Commission courts at Freetown and Havana, slave trade to be illegal after 30 May 1820 Form of Passport for Spanish Vessels destined for the lawful Traffic in Slaves Instructions for the British and Spanish Ships of War employed to prevent the illicit Traffic in Slaves Regulations for the Mixed Commissions, which are to reside on the Coast of Africa and in a Colonial Possession of His Catholic Majesty |
| 1820, 30 May | slave trade illegal |
| 1822, 10 Dec | Explanatory Article to the Treaty of 23 September 1817: also condemnation if slaves had been carried Additional Article to the Treaty of 23 September 1817: replacement of Commissioners |
| 1824, 2 Feb | Declaration explanatory of Additional Article: correction of clerical error |
| 1835, 28 Jun | treaty: equipment clause |
| 1840 | Valdez, Captain-General of Cuba diligent opponent of slave trade |
| 1845, 2 Mar | stringent legislation in Cortes; Spanish flag no longer used by slavers |
| 1850 | Cuban trade revives |
| 1869 | end of Cuban slave trade |
| 1886 | slavery abolished in Cuba |
| Sweden (and Norway) | |
| 1813 | slave trade illegal |
| 1824, 6 Nov | treaty: right of search (Mixed Commission courts not necessary as trade stopped) |
| Texas (independent from Mexico in 1836, joined United States in 1845) | |
| 1840, 16 Nov | treaty: right of search and national courts |
| Tuscany | |
| 1837, 24 Nov | treaty: right of search and national courts |
| Uruguay (independent from Brazil in 1828) | |
| 1839, 13 Jul | treaty: right of search and Mixed Commission court (only at Freetown, no Uruguayan commissioner) |
| USA | |
| 1807, 2 Mar | slave trade illegal |
| 1820 | slavery equated with piracy, punishable by death |
| 1821 | US navy squadron on the West African coast (until 1824) |
| 1836 | slavers sailing under American colours |
| 1840 | USS Dolphin (later USS Grampus) on the coast; Tucker-Paine cooperation |
| 1842, 9 Aug | Webster-Ashburton treaty: national courts, no right of search, US navy squadron on the West African coast |
| 1862, 21 Nov | death penalty under law of 1820 first exacted |
| 1862, 7 Apr | Washington treaty : right of search and Mixed Commission courts in Sierra Leone, Cape of Good Hope and New York |
| 1863 | slavery abolished in the north |
| 1865 | 13th amendment: slavery abolished |
| Venezuela | |
| 1839, 15 Mar | treaty: right of search and national courts |
The information on the page is derived primarily from Lloyd; Ward; and Bethell.
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