C. 1480 BC, fugitive slave treaty between Idrimi of Alakakh (now
) and Pillia of
Evidence of slavery predates written records, and has existed in many
 However, slavery is rare among
hunter-gatherer populations. Mass slavery requires economic surpluses and a high population density to be viable. Due to these factors, the practice of slavery would have only proliferated after the invention of agriculture during the
Neolithic Revolution, about 11,000 years ago.
Slavery was known in civilizations as old as
Sumer, as well as in almost every other ancient civilization, including
Ancient China, the
Roman Empire, the
Nubia and the
pre-Columbian civilizations of the Americas.
 Such institutions were a mixture of
debt-slavery, punishment for crime, the enslavement of
prisoners of war,
child abandonment, and the birth of slave children to slaves.