The history of slavery spans many cultures, nationalities, and religions from ancient times to the present day. However, the social, economic, and legal positions of slaves have differed vastly in different systems of slavery in different times and places.[1]
Slavery occurs relatively rarely among hunter-gatherer populations[2] because it develops under conditions of social stratification.[3] Slavery operated in the first civilizations (such as Sumer in Mesopotamia,[4] which dates back as far as 3500 BC). Slavery features in the Mesopotamian Code of Hammurabi (c. 1860 BCE), which refers to it as an established institution.[5] Slavery was widespread in the ancient world found in almost every other ancient civilization such as the Roman Empire. It became less common throughout Europe during the Early Middle Ages, although it continued to be practice in some areas. The Byzantine–Ottoman wars (1265–1479) and the Ottoman wars in Europe (14th to 20th centuries) resulted in the capture of large numbers of Christian slaves. The Arab slave trade encompassed the mainly in Western and Central Asia, Northern and Eastern Africa, India, and Europe from the 7th to the 20th century. The Dutch, French, Spanish, Portuguese, British and a number of West African kingdoms played a prominent role in the Atlantic slave trade, especially after 1600. The Republic of Ragusa became the first European country to ban the slave trade in 1416. In modern times Denmark-Norway abolished the trade in 1802.
Although slavery is no longer legal anywhere in the world (with the exception of penal labour),[6] human trafficking remains an international problem and an estimated 25-40 million people were enslaved as of 2013, the majority in Asia.[7] During the 1983–2005 Second Sudanese Civil War people were taken into slavery.[8] Evidence emerged in the late 1990s of systematic child-slavery and -trafficking on cacao plantations in West Africa.[