Slavery began in large form soon after humans first began to settle into collective organized groups large enough to be called what we could call towns (this refers to the number of people involved not the sophistication of the buildings). However scholars state that slaves ll numbers even before this.
This occured absolutely everywhere on earth, later vast numbers were taken by Arabs, where extremely large numbers died as many of them were required for Hareems (Islamic designated areas for Women only) where the males had to be eunuchs so they did not interfere with the Arab women. The Arab slave traders cut off the genitals with knives and the ones still alive once they`d walked over the desert to the ships were taken away. The huge attrition rate was irrelevant as the price paid for Eunuchs was enough to offset those who bled to death in the sand for whom very little had been paid. So they simply took far more than were needed, knowing that the final price was worth it, and was far less effort than looking after those medically who had been mutilated. Some alternatively had their genitals cut off in designated rooms at the ports, and were simply thrown overboard when they died.
When Europeans arrived, they didnt even have to travel inland or "take" slaves, as they simply contacted the african warlords who were already selling slaves from local rival tribes, the Europeans were merely the latest buyers to arrive. It is estimated that about 90% of all slaves Europeans removed from Africa, were simply purchased upon arrival there.
en.wikipedia.org/wiki/Slavery_i…
The first nations to decide that this was no longer tenable were Iceland and Norway, however these were internal policies with no external effects, more serious measures were taken by Haiti and Denmark, who actually included abolition of the transatlantic trade.
Britain began stopping the trade with the The Slave Trade Act of 1807. Later the British Slavery Abolition Act of 1833 represented the FIRST legislative act in the world, which not only began the process of banning the internal use of slaves, AND the trade, but also included active external use of military force to STOP the practise elsewhere. The British expended significant military effort stopping the trade, and then eventually bought the freedom of the slaves in our lands, at immense cost in 1833, the loan was only paid off in 2015.
The British nation at the time spent the about 2% GDP for a considerable time on stopping slavery. About three thousand Royal Navy personell were involved in this interdiction effort.
It is difficult to make exact figures, but the largest slave users in known history since reasonable records began was the Roman Empire, with about 10 to 15 million slaves at the peak of the empire in captivity, which were mostly white European in origin with countless nationalties, including Britons, Germans, Greeks and Spaniards, some africans were also used.
unrv.com/slavery.php
The second most prolific users of slaves were Arab/Islamic nations, with about 11 > 18 million slaves in use, spanning well over a thousand years of exploitation. These were taken from Africa, India and Europe, and included many white europeans.
soamibooks.com/post/the-islam…
The third was the Portuguese Empire, which is estimated to have taken about 6 million slaves from Africa specifically.
statista.com/statistics/115…
The forth was the British empire which took about 3 million slaves, mostly from Africa over about 170 years.
slaveryandremembrance.org/articles/artic…
The fifth was the French empire, which took about a million slaves, mostly from Africa.
encyclopediavirginia.org/entries/transa…
Unlike the Arabian and Islamic nations who used slaves for well over a thousand years, Britain in just 170 years went from using slavery, to banning and then bring the first to militarily enforce this ban internationally.
We do not know exactly how many black Africans over time were enslaved by other black Africans for use internally within Africa, but we know it was utterly endemic to the societies there, and was was vast in scope. Estimates range from 25% to 75% of Africans in different parts of Africa for a large period in history existed on some level essentially as slaves to other Africans, although some had better life conditions than others and in some regions could expect after a long period of service to possibly be released.
ldhi.library.cofc.edu/exhibits/show/…
I hope this leaves you marginally better informed about this terrible period in human history, which, is still very much ongoing in many parts of the world today.
