“O you men! We have created you of a male and a female, and then We made you (into different) races and tribes so that you may know each other. Surely the most honourable of you with Allah is the one who is most pious among you; surely Allah Is All-Knowing & Aware.” (The Qur'an 49:13)
Slavery was not an institution invented by Christianity or Islam. It was there long before these religions came into being. Just to give a glimpse of ancient slavery, let me quote from Justice Ameer Ali:
The practice of slavery is coeval with human existence. Historically its traces are visible in every age and in every nation...The Jews, the Greeks, the Romans and the ancient Germans, people whose legal and social institutions have most affected modern manners and customs, recognised and practised both kinds of slavery, praedial servitude as well as household slavery. With establishment of the Western and Northern barbarians on the ruins of the Roman empire, besides personal slavery, territorial servitude, scarcely known to the Romans, became general in all the newly settled countries...The barbaric codes, like the Roman, regarded slavery as an ordinary condition of mankind; and if any protection was afforded the slave, it was chiefly as the property of his master, who alone, besides the State, had the power of the life and death over him.1
In Persia the palace of the Emperor had twelve thousand women slaves. When the Byzantine Emperor sat on the throne, thousands of slaves remained in attendance with full attention and hundreds of them bowed when he bent to put on his shoes. In Greece, the number of slaves was far greater than the number of free men, although Greece had produced great advocates of humanity and justice. Every Greek army which entered with ridings of victory over the enemy was followed by a host of slaves.
Aristotle, the famous ancient philosopher, while discussing the question whether or not any one is intended by nature to be a slave, says, “There is no difficulty in answering this question, on grounds both of reason and of fact. For that some should rule and others be ruled is a thing not only necessary, but expedient from the hour of their birth, some are marked out for subjection, others for rule.” Then he concludes, “...some men are by nature free, and others slave, and that for these latter slavery is both expedient and right.”2
With Imperial Rome, the slavery of the ancient world reached its zenith, but when Roman Empire began its decline, the lot of slaves began to improve in some tiny degrees. But the canker of slavery was too evident. It had defeated the skill of Roman legality as it had defeated the subtlety of Greek philosophy. To be compassionate with slaves was regarded not as a natural feeling but as a personal idiosyncrasy. The slave was hardly human; he had no right, he had no soul.3
At the time of the advent of Islam (in 7th century CE) slavery was rampant throughout India, Persia, Rome, the Arabian Peninsula, Rumania and Greece. The elite and educated class of these countries did not regard the slaves eligible even for the basic human rights. He was regarded as a commodity not worthier than cattle.4 Often he was sold cheaper than sheep and goat. On special social occasions the distinguished citizens of the State used to get together with the Head of the State to watch the gladiatorial games in which the slaves were made to fight with swords and spears just like the shows of cock-fights and partridges in our old feudal society. The people cheered the hands until one of the fighters was killed. The audience would then applaud the winner heartily.5
On the one side, the Arabian Peninsula was surrounded by countries which still bore traces of the grandeur of the then declining Roman-Greek civilisation, and on the other side, by countries wrapped in Zoroastrianism and Hinduism. As mentioned above, in all these countries slavery was a recognised institution. The twelve Tablets had given its official seal of approval to this institution. The unmitigated hardship and cruelty which the slaves were made to suffer had not abated but, if anything, the slaves were now accepted as animals whose fate was only to work and die for those who owned them. I do not intend this book to be a chronicle of the inhumanity which the slaves suffered but suffice it to say that man must forever carry in his conscience a sense of guilt for having once indulged in slavery.