The Full Story
Between 1822 and 1870, Britain signed over fifty treaties with African rulers. Lagos. Dahomey. Zanzibar. Abeokuta. The Gambia. Sierra Leone. And dozens more.
These weren't treaties of conquest or exploitation. Not primarily. Britain arrived with money and an ultimatum: close your slave markets. Free the captives. Or face consequences.
The pattern was consistent. British agents would negotiate with local rulers, offering annual payments, weapons, or trade advantages in exchange for abolishing the slave trade. Those who agreed received British support. Those who refused faced economic pressure, naval blockades, or in some cases, military intervention.
Some rulers, like King Radama of Madagascar, used British support to build empires. Others, like King Ghezo of Dahomey, initially agreed but later broke the treaty when they found the slave trade too profitable to abandon.
Fifty years. Fifty treaties. Paid to set people free.
Why This Matters
The treaty system shows how Britain's abolition efforts went far beyond simply banning the slave trade in British ships. Britain actively worked to end slavery across an entire continent, using every tool available: money, diplomacy, and when necessary, force.
Key Facts
- ✓Over 50 anti-slavery treaties signed with African and Arab rulers across 50+ nations and territories (multiple academic sources, Oxford University Press, Historic UK)
- ✓400,000 signatures on abolition petitions in 1792 (National Museums Scotland, Swarthmore Global Nonviolent Action Database)
- ✓300,000 families boycotted slave-grown sugar by end of 1791 (Thomas Clarkson's estimate, supported by historian Seymour Drescher)
- ✓~13% of adult male population signed petitions 1787-1792, "one in eight men" (Swarthmore database, multiple academic sources). Note: this figure refers to adult males specifically, not all adults. Women did participate in boycotts but formal petition signatures were predominantly male.
- ✓Slave Trade Act passed 25 March 1807 (Parliamentary records)
- ✓Britain pressured France, Spain, Portugal, Netherlands, Sweden into anti-slavery treaties (multiple sources including Cambridge chronology, Hansard)
- ✓West Africa Squadron formed 1808, patrolled until 1867 (Wikipedia, Royal Navy records, Historic UK)
- ✓~3,000 miles of West African coastline patrolled (multiple sources)
- ✓~1,600 slave ships captured (Wikipedia, Historic UK, Royal Navy records)
- ✓~150,000 people freed (Wikipedia, Historic UK, Royal Navy records, some sources say 150,000-200,000)
- ✓HMS Black Joke: captured Brazilian slave ship Henriquetta 1827, repurposed by Royal Navy, captured 11 slavers in one year (Wikipedia, TIME, multiple sources)
- ✓Zanzibar: 11 anti-slavery treaties and decrees between 1856-1897 (Cambridge Core, Britannica)
- ✓King Kosoko of Lagos deposed December 1851 for refusing to end slave trade (Wikipedia, multiple sources)
- ✓~1,600 sailors died 1830-1865, predominantly from tropical disease (Full Fact verified figure, the widely circulated 17,000 figure is FALSE and debunked)
- ✓❌ The "17,000 sailors died" or "one sailor per nine slaves freed" claims are NOT supported by evidence (Full Fact debunked)
- ✓"The white man's grave", common contemporary name for West African posting (multiple sources)
- ✓£20 million compensation paid to slave owners under Slavery Abolition Act 1833 (Treasury records, Full Fact, multiple sources)
- ✓£20 million = ~40% of Treasury annual income / ~5% of GDP (multiple academic and financial sources)
- ✓Government gilts traceable to the 1833 slavery compensation loan were retired on 1 February 2015 (HM Treasury confirmation, Full Fact). The original loan was refinanced multiple times, notably into consolidated government bonds in 1927, but the debt instruments were continuously serviced by taxpayers until formal retirement in 2015.
- ✓"You or your parents were still paying for it", any UK taxpayer before February 2015 was contributing to government revenue that serviced bonds traceable to the 1833 loan. Defensible as a general statement.
- ✓"It outlasted the Empire itself", the British Empire effectively ended mid-20th century (Indian independence 1947, decolonisation through 1960s-70s). The slavery compensation debt was not retired until 2015. Inarguable.
- ✓Over 14% of the entire Royal Navy deployed to anti-slavery patrols at peak (academic sources)
- ✓310 petitions received by Parliament in 1792, greatest number on a single subject to that date (multiple sources)