Slavery has existed in India since the time of the Mauryas at least.
(around 300 bc).
However, since Indian society has throughout been subject to the
strictly-enforced caste system, the differences between those in the
lowest caste and the lot of the slaves are not very great and, in some
cases, it may have been better to be a slave.
A large number of slaves appear to have been sourced from Greece and Greek
colony cities. This is shown both by written records and by
illustrations of the people involved. The female slave armies that
protected the king's harem were frequently known as Ionians and fought
hard to maintain the traditions, names and language of their homelands.
Other slaves were bought by traders from the west, bringing people
from Africa, Arabia and from time to time, no doubt, the European
mainland as well. Traders in eastern waters surely did the same, with
slaves brought from Sri Lanka and Southeast Asia. It was also possible
for free-born Indians to become slaves, perhaps through a court
decision after having committed a serious crime. Others might be
enslaved as a result of war or trafficking but it was also possible for
people to put themselves up for enslavement. They could put their
freedom at stake as surety for a cash loan or for a gambling stake.
However, enslavement need not be permanent. A financial arrangement
could be made in these cases but, if worst came to worst, slaves were
allowed one chance to try to escape and, if they managed to get away,
they were permitted to claim their freedom permanently.