Slavery as a result of debt, however, existed in very early times, and some African peoples have had the custom of putting up wives and children as hostages for an obligation; if the obligation was unfulfilled, the hostages became permanent slaves.
Slavery was an established institution in the Greece of Homers time, and a large portion of the population of the Greek city-states in later days were of the servile class.
At any rate, the abolition legislation of 1833 was followed by the gradual abolition of slavery in all lands under British control, principally by the device of invalidating the legality of slavery and removing its legal safeguards, usually by recompensing the owners.
Historically, slavery has generally occurred as a means of securing the labour of the slave, without the right of the slave to refuse, leave or receive anything in return for thie labour other than food, accommodation and clothing.
The legal presence of slavery has become rare in modern times, as nearly all societies now consider slavery to be illegal, and persons held as in such condition are considered by authorities to be victims of unlawful imprisonment.
Slavery was not a cost free enterprise, slaves were seldom paid a wage, but the owners were responsible for feeding, housing, clothing, providing simple medical care, and (in some rare cases) education for all of the slaves' lives from birth to death.