Slavery is an institution wherein a person is legally owned by another and forced to work for them. Slaves (dàsa), like other property, can be brought, sold and mortgaged. In ancient India there were four types of slaves - those born into slavery, those enslaved because of debt, prisoners of war and those who sold themselves into slavery, e.g. during famine.
The Buddha said that the buying and selling of human beings is a wrong means of livelihood for lay people (A.III,207) and he forbade monks and nuns to accept gifts of slaves or to own them (D.I,5). These teachings seem to be the oldest known prohibition against slavery. Despite this, slavery existed in all Buddhist countries as it did everywhere in the world. When it was abolished in Buddhist lands, this was done by the colonial powers - in Sri Lanka in the 1820’s and in Burma, Laos, and Cambodia at the end of the 19th century – and in Thailand due to pressure from Western governments. The last county in the world to abolish slavery was Bhutan in 1962, although slavery continued to exist in parts of the Middle East for at least another two decades after that.